I’m thrilled to announce the second Sci-fi Interfaces Movie Night, again in the New Parkway Cinema in Oakland. This time it’s the amazing meta sci-fi and horror fest from the minds of Joss Whedon and Drew Goddard, The Cabin in the Woods. (Kristen Connolly! Chris Hemsworth! Anna Hutchison! Fran Kranz! Jesse Williams! Richard Jenkins! Bradley Whitford!) Enjoy this amazing film the way it was meant to be enjoyed: With a bunch of other sci-fi nerds, on the big silver screen, with a pre-show, tables, couches, food, and a bar.
This one is going to be bigger, gorier, and better than the last, with sci-fi and a heaping helping of metahorror to get you amped up for Halloween later in the week.
A few folks had asked if we could move into the smaller cinema at The New Parkway. We could, but there are two problems with it. First, it would have raised the ticket price even more since there’s less seating. Second, that cinema can not connect to a computer for any pre-show visuals. So, we’re sticking with the large cinema.
As before, I’ll make a short presentation deconstructing and analyzing one of the interfaces in the movie, as well as running a trivia contest with at least The Cabin in the Woods sci-fi interface t-shirts as prizes. I’m working on a way to let everyone in the audience participate this time, via their smart phones or something.
If you attended the last one, and you have other ideas about how it can have its awesome quotient increased, contact me or leave a comment here.
So it turns out there’s already a cool event happening at The New Parkway on Thursday 30 October from 6:30—9:30 P.M., which doesn’t leave a whole lot of options. But, which of these work best for you (and whoever you might want to invite)?
Please share the poll with everyone you think might want to come!
Note: This polldaddy doesn’t work on Chrome. Head to Firefox if you want to cast a vote!
Sci-Fi Interfaces Movie Night is back this fall, just in time for Halloween! I’m in talks currently with The New Parkway in Oakland, CA to license one of my favorite horror/sci-fi crossovers The Cabin in the Woods!
I’ll have some of the kinks worked out from the first movie night (a trivia contest that everyone can participate in, easier questions, better seating in the 100-seat cinema—though ticket costs may rise) and I’m working on some amazing additional surprises. Can’t spill the beans yet, but even my mind is blown.The first order of business for this amazing event is to find out who is interested: Would you be? You can let me know how excited you’d be for such an event on a scale of 1 to Oh My Stars in the comments.
Also, the cinema and I are wondering what night would be best for the event. The options are all during Halloween-week, but the question is which night:
Wednesday the 29th
Thursday the 30th
Friday the 31st
Answer this poll and let me know what night would make the most sense with your plans for that week.
And as before, the likelihood of the event depends on the amount of interest there is. If you want to make sure it happens, spread the word and share this URL with everyone you think would be interested.
Chris Kieffer and Copin Le Bleu ran across my interview with Shaun Yue, and since they had done the interfaces for The Cabin in the Woods, contacted me eager to share their story as well. Since Cabin has the highest-rated interfaces in the Make It So survey so far, I was very glad to have the chance to talk with them as well. So in honor of the one-year anniversary of the film’s release…
What brief did you receive? How did you interface with (director) Drew Goddard?
COPLIN: The one thing I really remember was that the control room needed to have an older feel to it, like it had been set up years ago but still functional… a kind of a low tech mechanical feel with high tech functions. I remember referencing photos of security/surveillance control rooms that you would see in a prison guard station. I didn’t communicate with Drew directly. All notes got were filtered down from the on set playback operator and supervisor.
CHRIS: When we started this project, design notes from Drew were given to our on-set playback supervisor Mike Sanchez in Canada, to relay to us here in the U.S. The notes said the control room is to look like its been there for a long, long time. As if they built this room with state of the art equipment years ago, but over time they have made some upgrades but kept the old stuff that still works there. So you could have a modern computer running software right next to an old light up panel with switches on it that work together.
Tell me how you went about creating the interfaces for The Cabin the Woods? How did you handle the remote collaboration between you two?
COPLIN: I started designing the interface with the idea that it was an older system set up, that might have looked high tech in it’s prime but had "weathered" a little bit. So I tried to add a lot of terminal and DOS style elements that would imply a lower, underlining level of programing. I also felt it needed to have a utilitarian and mechanical feel to the design as it would be controlling and monitoring the different parts of the house. Chris and I were in the same office, although we were balancing multiple projects together at that time.
CHRIS: Coplin started the initial design on the interface, but we had a few variations of interfaces to make. I started designing different parts of the system like the video surveillance setup and background screens that included video oscilloscopes, code screens, door keypads, and a lot of surveillance on different monitors. The remote aspect came into play when things needed to get approved or changed. We would send the files to Mike in Canada for Drew to look at, and if changes were needed he would send us drew’s notes. So there was a delay sometimes in getting things approved which made it harder to get things made in such a short time.
Were there any great ideas that didn’t make it to screen? What would you go back and redo given the opportunity?
COPLIN: Looking back on this project, there were a lot of ideas that I’m glad did not make the film. After reading the review on your blog (a very humbling and at times embarrassing experience), there are plenty of changes I would’ve made. One in particular is the idea of making the deaths on the "kill" screen less noticeable as that information would be less important for their mission. There’s not usually a lot of time to spend on the details. My first requirement is to tell the story point efficiently and effectively as I can. I would have liked to have had more time think about the details of the designs.
CHRIS: Yes, at one point we talked about having a monster select screen that showed all the monsters and their stats. That would have been fun to make but we were early in production and they hadn’t picked/designed all the monsters yet, so that was never finished. After I finish any project I learn so much and always look back and say I could have done this or that, but there’s never enough time.
What are your backgrounds? Are you interface designers or SFX artists by training?
COPLIN: I have a Bachelor of Arts degree in TV/Film Production from the University of New Orleans. After college I became a self-taught motion graphics artist.
CHRIS: I have a BS in visual Communications, and an AS in Graphic Design. I started in print, designing packaging, advertising, and product design. I really liked animating graphics much more than print and so went in that direction instead.
What were the biggest challenges working on the film?
COPLIN: Time, as in all productions, seems to be one of the biggest challenges, as well as not physically being on set. I find being on set helps me with designing the functionality of the screens, to see how they will be set up in their environment and how the surrounding set pieces interact with them. Also it was very challenging for me to display a lot of "nondescript" information to make the screens look busy without tying that graphic to what ever pertinent plot point might be going on at the time.
CHRIS: I agree with Coplin on this one. We only had a couple of days to design and animate all the screens for the main control set. That includes making changes on the fly. It does make it hard not being there, not being able to see the actual set and see how something looks on a monitor and being able to adjust it. Then we have the “make it bigger, and red or green” problems. This is when we have to make some text on the screen very large and red if bad and green if good. We try very hard to avoid things like that but sometimes it’s out of our control. They need to get a specific point across to the audience quickly, and even though your computer wouldn’t say something like "Access Denied" in RED 72pt FONT, some of these just might.
What interfaces are you most proud of in the film? (And, of course, why?)
COPLIN: I guess I’m most proud of the "Penta-Vitals" aka "Marking the deaths" screens. They’re dense and busy but I feel like you could easily at a glance tell who was where and how they were feeling.
CHRIS: I actually liked making the older electronic equipment screens. The oscilloscope, waveform monitors, were a challenge to make look real. I found making the older tech screens look real was a lot harder than I thought. The look and feel they had on those tube monitors is almost impossible to match on an LCD or plasma, but some we made for tube monitors.
What’s your favorite sci-fi interface that someone else designed?
CHRIS: I like a lot of interfaces I see in films and tv shows, but off the top of my head I really like the look and movement of Ash Thorps recent work on Total Recall
In your opinion, what makes a great sci-fi interface designer?
COPLIN: I think what makes a great sci-fi interface designer is someone who can artistically tell the story and creatively display pertinent information in a clear and concise manner. Someone who can put themselves in the characters shoes and imagine what that character would want to see on the screen.
CHRIS: I agree, a designer should find a way to solve a problem or create a user interface that is fast and relevant to the story while making it artistically appealing to look at.
What’s next for you?
COPLIN: I’m hoping to continue creating interactive motion graphics for on-set video playback and post production.
CHRIS: To continue working on interface design and animation for films and tv shows. Im starting on a new project right now designing a 3d Holographic navigational control system, and some HUDs for some space suits.
From the sudden and hilarious appearance of the title on screen, I knew that The Cabin in the Woods was going to be a special film. And in fact, it is one of my favorite movies of the past year, and dare I say one of the best sci-fi/horror hybrid movies of all time. (Admittedly it’s not a giant subgenre.) When we focus on the interfaces, they ultimately help tell this dark story of epic comeuppance, even if they stumble a bit on the details.
Sci: B+ (3 of 4) How believable are the interfaces given the science of the day?
The surveillance and control interfaces are all perfectly believable, even as they span different technological paradigms. There are some aspects of the interface that must be excused as “mystical,” and some toying with chemical science, i.e. human sex pheromones and the “let’s split up” chemical, that prevent us from awarding it full marks.
Fi: A (4 of 4)
How well do the interfaces inform the narrative of the story?
In addition to helping set the stage of a service that spans technological eras, nearly all of the problems help tell the story of a controlling organization that is only barely in control. It’s dysfunctional and jaded enough in the execution of its dark duty that we’re kind of OK with their failure and ultimate destruction. And much of the rest of the problems can be swept under the narrative rug of “it’s mystical,” again, in a very smart way. The only thing that takes us out of the narrative to ask “why” and “how” is the inexplicable cause-failure SYSTEM PURGE switch, but it ultimately just sped up a part of the film that could have been too slow in the wrong part.
Interfaces: C (2 of 4)
How well do the interfaces equip the characters to achieve their goals?
There’s lots of goodness in the interfaces to learn from: Solid clustering of monitoring signals, strong physical differentiation in the control dashboard, and even well-protected and well-labeled kill switches. But there are equally large problems as well: There are several blind controls that only permit expert use. There’s an escape hatch security system that only increases the panicked user’s panic. The communication system between the humans and Old Ones is ambiguous enough to cause world-class failures to communicate. For these reasons, you should be careful when pulling lessons for the real world from the interfaces found here.
Final Grade B+ (9 of 12), MUST-SEE
Related lessons from the book
The delightful mechanical controls in the film already embody the lesson Mix Mechanical and Other Controls Where Appropriate. (page 26)
Those same controls might have used some smarter grouping as seen in Chapter 3, Visual Interfaces. (page 55)
The control room interfaces should have remembered the lesson from the Communication Chapter, that Signaling Change of State isn’t Enough. (page 202)
The course-correction interfaces that nudged Jules and Curt into sex started to fulfill the Sex chapter’s Augment Everything opportunity. (page 301)
Suggested new lessons
The excellent differentiation seen in the control panel suggests a new lesson to Differentiate Physical Controls, such that they are easy to find by touch, and tell apart immediately.
There is another set of users of the Global Sacrifice System who bear a bit of consideration, and they are the Old Ones. They are users in the sense that this is an agreement into which they’ve entered with humanity, in order to get a continuing IV drip of (to them) pleasurable abject suffering and death. This isn’t an imposed frame on the story. The ritual spoken by Sitterson are not the words of a zookeeper managing a downed animal’s Ketamine. They’re the words of a supplicant.
As long as the organization keeps the sacrifices coming, providing the tasty intravenous drip of human suffering, the world is allowed to continue as it is for another year. With this in mind, we can analyze how the system works for those users, i.e. the Old Ones.
The outputs that the Old Ones read from the system are unavailable to us, but we can tell it’s kind of precise. There are allusions midway through the film that the titan below the cabin is somehow “watching” the sex scene. (Though that ambiguous line could refer to the ravenous horror-movie audience as well.) It can also somehow sense the suffering of the victims, and whether the details of the ritual are being carried out in the proper order. The way we know this is that when Marty’s “death” vial is inappropriately shattered, the titan causes an earthquake that rocks the complex and the cabin.
This, then, is the input that the Old Ones have: shaking the ground in their displeasure. But as a signal, it’s far too vague. Hadley and Sitterson feel the quake, but disregard it. Hadley shouts, “They must be getting excited downstairs!” and Sitterson replies somewhat jadedly, “Greatest show on earth.” Had they had any inkling that they had actually messed up (even absent of what precisely was messed up) they would have pulled out the stops to find the error and correct it.
So while we as an audience are all in favor of resetting of a world that has accepted annual ritual sacrifice of young people, neither party to the agreement—the Old Ones nor the humans—set in place a system of communication that is precise enough to keep the agreement going. And that’s a failing of the interface.
The breach is not well-handled by the systems around the control room. Not only do the lights not have a local backup power source, but the screens on the background display Big Labels saying unhelpful things like, “ESCAPE ALERT – UNKNOWN SECURITY BREACH.” If you were designing a system specifically to control nightmare monsters to sacrifice helpless victims, I think the first thing your risk officer should work out is a system that can recognize and withstand when one of those two things (monsters or victims) was out of place. The least you could do is provide users with extremely clear status messages about them.
Sitterson and Truman scan the video monitors for Dana and Marty.
After the breach, we see one more interface for the stage managers: an old escape route. Even though Control is world-critical, its designers imagined that things could go haywire. Presuming that other scenarios are going fine, if all hope is lost in this one, the stage managers have a way out of the control room. We only get a few glimpses of this interface, but it looks to be a computer-controlled security access lock whose 8-bit graphics imply that it was implemented in the early 1990s, around the time when Microsoft Windows 3.1 was the dominant computing paradigm.
Sitterson desperately enters his PID.
After working desperately a bit, Sitterson is able to get the system to a screen that asks for his PID. He uses a rubber-key keypad below the screen to enter it, and is told “SECURITY OVERRIDE GRANTED.” In this way he is able to open the trap door and escape the monsters swarming the control room.
Especially given the amount of stress that a user is likely to be under while using this interface, and the infrequency with which it must be used, it seems absolutely cruel to secure the door by a memorized identification number. Unless that PID is used frequently enough to become habit, it’s unlikely to be remembered when the user is trying to escape death. Better is to use the ID cards already seen in the film in combination with some biometric scan like retina or finger print.
There is a system in place to manage the “resources,” the nightmare creatures available to be chosen by the victims for their sacrifice. This management includes letting them out to the surface, putting them back in place safely, and containment throughout the intervening year between sacrifices.
Dana and Marty experience the cages from the perspective of a monster
The one interface element that we do see in use is the one that Dana and Marty use to release the imprisoned nightmare monsters throughout the complex. It is a single kill-switch button labeled “SYSTEM PURGE”, located on a panel in the security booth that overlooks the main elevator bank. While hiding from approaching security forces, Dana notices the switch beneath the monitoring screens. She flips a protective switch cover to enable it, sees a confirming amber light, and then slams down on the kill switch. Moments later, the first of several waves of nightmare monsters are released through the elevator doors into the complex.
Dana slams the System Purge kill switch.
From a story viewpoint, this is an awesome moment where the story becomes utter chaos and the workforce of jaded sacrificers get their horrible, horrible come-uppance. But from a design standpoint, it’s utter nonsense. Imagine a nuclear power plant where the kill switch, which is accessible through an unlocked door and labeled clearly for any saboteur to read, dumps live fuel rods and heavy water onto the heads of the plant operators. Or a zoo where the animals-are-furious-and-hungry switch dumps the animals right onto the grounds. A system like Control, with global reach and resources, would find some other space into which this murderous tsunami can be vented, and ensure proper security around the activation mechanism. Still, this makes for hilarious chaos and the “happy” ending, so as audience members we’re glad Control messed up on its design strategy.
Marty had already been shown to be able to hack Control’s electronics upstairs, so I suspect the narrative decision about the purge switch was made to give Dana some additional agency in this part of the story, and add some punch to the onset of the final act, so we’ll count that as a minor quibble, too.
The stage managers’ main raison d’être is to course-correct if and when victims begin to deviate from the path required of the ritual.
This begins with the Prep team, long before the victims enter the stage. For example, Jules’ hair dye and Marty’s laced pot. These corrections become more necessary and intense once the victims go on stage.
Making sure there are sexy times
The ritual requires that a sexy young couple have sexy times on stage before they suffer and die. “The mood” can be ruined by many things, but control has mechanisms to cope with most of them. We see three in the movie.
The temperature can’t be too hot or too cold, but this isn’t something that can be set and forgot. What counts as the right temperature is a subjective call for the people involved and their circumstances, such as being drunk, or amount and type of clothes worn. Fortunately, the video-audio panopticon lets the stage managers know when a victim speaks about this directly, and do something about it. The moment Jules complains, for instance, Sitterson is able to reach over to a touch-screen display and tap the temperature a few degrees warmer.
Sitterson heats things up.
The gauge is an interesting study. It implies a range possible between 48 and 92 degrees Fahrenheit, each of which is uncomfortable enough to encourage different behaviors in the victims, without the temperature itself being life-threatening.
Moreover, we see that it’s a “blind” control. Before Sitterson taps it, he is only shown the current temperature as a blue rectangle that fills up four bars and that it is exactly 64 degrees. But if he knew he wanted it to be 76 degrees, what, other than experience or training, tells him where he should touch to get to that desired new temperature? Though the gauge provides immediate feedback, it still places a burden on his long-term memory. And for novice users, such unlabeled controls require a trial-and-error method that isn’t ideal. Even the slim area of white coloring at the top, which helpfully indicates temperatures warmer than cooler, appears too late to be useful.
Better would be to have the color alongside or under the gauge with smaller numbers indicated along its length such that Sitterson could identify and target the right temperature on the first try.
The next thing that can risk the mood is a lack of a victim’s amorous feelings. Should someone not be “feeling it,” Control can pipe sex pheromones to areas on stage. We see Hadley doing this by operating a throttle lever on the electronic-era control panel. After Hadley raises this lever, we see small plumes of mist erupt from the mossy forest floor that Jules and Curt are walking across.
Hadley introduces pheromones to the forest air.
This control, too, is questionable. Let’s first presume it’s not a direct control, like a light switch, but more of a set-point control, like a thermostat. Similar to the temperature gauge above, this control misses some vital information for Hadley to know where to set the lever to have the desired amount of pheromone in the air, like a parts-per-million labeling along the side. Perhaps this readout occurs on a 7-segment readout nearby or a digital reading on some other screen, but we don’t see it.
There is also no indication about how Hadley has specified the location for the pheromone release. It’s unlikely that he’s releasing this everywhere on stage, lest this become a different sort of ritual altogether. There must be some way for him to indicate where, but we don’t see it in use. Perhaps it is one of the lit square buttons to his right.
An interesting question is why the temperature gauge and pheromone controls, which are similar set-point systems, use not just different mechanisms, but mechanisms from different eras. Certainly such differentiation would help the stage managers’ avoid mistaking one for the other, and inadvertently turn a cold room into an orgy, so perhaps it is a deliberate attempt to avoid this kind of mistake.
The final variable that stands in the way of Jules’ receptiveness (the authors here must acknowledge their own discomfort in having to write about this mechanistic rape in our standard detached and observational tone) is the level of light. After she complains that it is too dark, Hadley turns a simple potentiometer and the “moonlight” on a soft bed of moss behind them grows brighter.
Control responds to Jules’ objection to the darkness.
This, too, is a different control than the others; though it controls what is essentially a floating-point variable. But since it is more of a direct control than the other two, its design as a hard-stop dial makes sense, and keeps it nicely differentiated from the others.
Marty’s Subliminal Messages
Over the course of the movie, several times we hear subliminal messages spoken to directly control Marty. We never see the inputs used by Control, but they do, at least on one occasion, actually influence him, and is one of the ways the victims are nudged into place.
Marty breaks the fourth wall
In addition to Dana & Curt’s almost not getting it on, another control-room panic moment comes when Marty accidentally breaks a lamp and finds one of the tiny spy cameras embedded throughout the cabin. Knowing that this level of awareness or suspicion could seriously jeopardize the scenario, Hadley bolts to a microphone where he says, “Chem department, I need 500 ccs of Thorazine pumped into room 3!”
Marty finds a spy camera
Hadley speaks a command to the Chem department
Careful observers will note while watching the scene that a menu appears on a screen behind him as he’s stating this. The menu lists the following four drugs.
Cortisol (a stress hormone)
Pheromones (a category of hormonal social signals, most likely sex pheromones)
Thorazine (interestingly, an antipsychotic known to cause drowsiness and agitation)
Rhohyptase (aka Rhohypnol, the date rape drug)
Given that content, the timing of the menu is curious. It appears, overlaid on the victim monitoring screen, the moment that Hadley says “500.” (Before he can even specify “Thorazine.”) How does it appear so quickly? Either there’s a team in the Chem department also monitoring the scene, and who had already been building a best-guess menu for what Hadley might want in the situation and they just happened to push it to Hadley’s screen at that moment; Or there’s an algorithmic voice- and goal-awareness system that can respond quickly to the phrase “500 ccs” and provide the top four most likely options. That last one is unlikely, since…
We don’t see evidence of it anywhere else in the movie
Hadley addresses the Chem department explicitly
We’d expect him to have his eyes on the display, ready to make a selection on its touch surface, if this was something that happened routinely
But, if we were designing the system today with integrated voice recognition capabilities, it’s what we’d do.
Curt suggests they stick together
After the attack begins on the cabin itself, Curt wisely tells the others, “Look, we’ve got to lock this place down…We’ll go room by room, barricade every window and every door. We’ve got to play it safe. No matter what happens, we have to stay together.” Turns out this is a little too wise for Hadley’s tastes. Sitterson presses two yellow, back-lit buttons on his control panel to open vents in the hallway, that emit a mist. As Curt passes by the vents and inhales, he pauses, turns to the others and says, “This isn’t right…This isn’t right, we should split up. We can cover more ground that way.”
Sitterson knocks some sense out of Curt.
This two-button control seems to indicate drug (single dose) and location, which is sensible. But if you are asking users to select from different variables, it’s a better idea to differentiate them by clustering and color, to avoid mistakes and enable faster targeting.
Locking the doors
Once the victims are in their rooms, Hadley acknowledges it’s time to, “Lock ‘em in.” Sitterson flips a safety cover and presses a back-lit rocker switch, which emits a short beep and bolts the doors to all the victims’ rooms at the same time.
Sitterson bolts the victims’ doors.
Marty in particular notices the loud “clunk” as the bolts slide into place. He tests the door and is confounded when he finds it is, in fact, locked tight. Control’s earlier concern about tipping their hand seems to matter less and less, since this is a pretty obvious manipulation.
The edge of the world
Bolted doors pale in comparison to the moment when Curt, Dana, and Holden violently encounter the limits of the stage. After the demolition team seals the tunnel to prevent escape that way, Curt tries to jump the ravine to the other side so he can fetch help. Unfortunately for him, the ravine is actually an electrified display screen, showing a trompe-l’œil illusion of the far side. By trying to jump the ravine, Curt unwittingly commits suicide by slamming into it.
Curt slams into the edges of the “world” of the cabin.
The effect of the screen is spectacular, full of arcs zipping along hexagonal lines and sparks flying everywhere. Dana and Holden rush to the edge of the cliff to watch him tumble down its vast, concave surface. It seems that if you’ve come this far, Control isn’t as concerned about tipping its hand as it is finishing the job.
We know in the film that Control has been working behind the scenes long before the event takes place. The Chem department, for example, has somehow gotten Jules to bleach her hair, and the hair dye “works its way into the blood” as a way to slow her cognition, and make her conform more the Whore archetype. Additionally, they have been lacing Marty’s marijuana to keep him dazed & confused. (Though, key to the plot, they missed his secret stash.) There’s even an actor placed en route to the eponymous cabin who unsettles the victims with his aggression and direct violent insults to Jules, setting the stage for their suffering. Though these things occur “off stage” of the actual cabin (and the Chem team works off screen), they help tell the story about how deeply embedded Control is in the world, and set the stage for the surveillance interfaces on stage.
Marking the deaths: on screen & ritually
The goal of the scenario is the suffering and death of the victims, in the right order. To provide a visual marker on the monitoring screens, a transparent red overlay is placed over victims who are believed to have been killed.
The choice of red has a natural association with the violence, but red has a number of problems. Visually, it vibrates against blue (according to opponent process of color theory, the red and blue receptors in our retinas are in the same place and can’t perceive both at the same time). It’s also typically used to grab attention, which in this case is the exact wrong signal. Jules is no longer in the picture, and so specifically no attention is needed for her. Better would be to dim her section on the monitor, or remove her altogether, if marking progress is unimportant.
Hadley orders Thorazine
In addition to marking the deaths in the digital interfaces, the deaths must be marked ritually for the system to work. To this end, Sitterson and Hadley act as the human interface that transfers the information from the electronic systems to the Bronze-Age mechanical systems behind him. Though this could be accomplished mechanically, there are ritual words that must be spoken and an amulet that must be kissed by a supplicant.
Sitterson, the senior of the two, recites, “This we offer in humility and fear / For the blessed peace of your eternal slumber / As it ever was.”
After these ritual actions, Hadley raises a roll top wooden panel to reveal a simple switch. Pulling it down initiates a chain of mechanics that ultimately break a vial of blood into a funnel, which channels the blood into grooves carved into a sacrificial slab.
Sitterson and Hadley mark the first sacrifice
The roll top door acts as a physical barrier against accidental activation, and the mechanical switch requires a manageable, but deliberate, amount of force. Both of these features in the interface ensure that it is only done when intended, and the careful mechanical construction ensures that it is done right.