When Zorg believes he has recovered the sacred stones, he affixes a bomb to the door of Plavalaguna’s suite. The bomb is a little larger than a credit card, with a slot at the top for a key card to be dropped in. The front of the bomb houses all the buttons and lights. The bottom and top edges are rounded back.
The interface for the bomb is quite simple. Zorg presses three large, transparent buttons along the top in order from left to right to activate the bomb. These buttons glow bright red during the countdown. Below these buttons, four red LEDs blink in succession counting off quarter seconds. At the bottom of the display a 4-character, 7-segment timer counts down from the time set: 20 minutes. The device audibly ticks off each second as it passes.
An (adhesive? magnetic?) backing lets Zorg simply place the bomb on the wall to affix it there. Zorg presses the three large buttons in order from left to right to activate it and start the countdown.
The bomber is after simple activation, but also wants very much to avoid accidental activation. Pressing the buttons in order might happen accidentally, for example from a tire or foot rolling across it. Better would be to have the activation code something much less likely to happen accidentally, like 1-3-2 or 2-3-1.
There’s also a question of whether a bomber would put giant glowing lights, reflective yellow tape, or an audible tick on the bomb (LEDs, if you didn’t know, don’t come with a ticking sound built in.) Each of these draws attention to the bomb, giving helpless victims time to evacuate, alert the authorities, or inform any explosive ordnance disposal personnel that happen to be wandering by. Yes, Zorg wants the bomb to explode, but only after a certain time, so he can get away. He should affix the bomb in some hidden place and design it with a less attention-getting display to suit his fiendish goals.
Once Zorg realizes that the box he stole was empty, he returns to the Fhloston Paradise liner to look for the stones. His first task is to deactivate the bomb. To do this he pulls out a keycard, and gingerly holds it above the bomb. His caution and nervousness implies that it has a jostle-sensitive anti-handling sensors, and that if he bumped it, it would go off. Fortunately for him, he manages to slip the card in without jostling the bomb, and sure enough, it stops with five seconds to go.
The keycard is a mostly-smart deactivation strategy. As we can see, Zorg is quite nervous during the deactivation, and in such high-stress times, it’s better to rely on an object than a stressed villain’s memory for something like a password. The card is thin like a credit card and can fit in a wallet, so it’s easy to carry around. There’s a risk that the card could be misplaced, but the importance of the key will ensure that Zorg will keep track of it. There’s a risk it could be ruined and become useless, but we can presume Zorg made it with tough, ruggedized materials.
The problem with the shape is one of orientation. There are four ways a card can be oriented to a slot, and looking at the card, there is no clear indication of the correct one. The copper circuitry printed on both sides is asymmetrical, so it’s at least possible to tell the current orientation. Perhaps this is the “password” that the system requires, and the random stranger picking it up only has a one in four chance of getting it right.
Fortunately for Zorg, he remembers the correct orientation, and is able to stop the bomb.
Or, this bomb, anyway.