Make:

Today's the deadline for the latest MakeShift challenge, which graced the pages of MAKE, Volume 16. But since I forgot to remind you readers about the deadline, we're extending the deadline by 1 day, to Saturday, March 7 (tomorrow!).

Here's what you're up against:

Tick, Tick, Tick ...
The Scenario: You've worked late into the night as a computer engineer in the high-rise headquarters of an international bank, and you're finally heading with your briefcase to your car in the subterranean parking garage. Your car is the only one left on this dimly lit level, parked along a cement wall right near the elevator. But, as you pull out your keys and are about to hit the unlock button, you hear a loud beep behind you.
Startled, you turn to see an object against the wall just a few feet away with a pulsing red light on it -- and in the poor light, you can immediately make out an illuminated timer which is now ticking off the seconds from a 3-minute window!
There is a jumble of multicolored wires, and an array of three motion detectors set to cover a 180º field off the wall, all of which are wired into a small black box sitting on a large brick-shaped object that's slightly smaller than a shoebox. Also atop the brick and on its ends, you see three horizontal glass tubes that appear to contain mercury with wires at both ends, as well as a metallic-looking cylinder with several long wires jammed into the side of the brick-like mass. There's little doubt left in your mind now that this is a bomb! -- and your arrival here must've set off the timer.
The Challenge: Though you know how mercury switches work, you're uncertain of the purpose of the motion detectors, or of the black box -- could it contain a hidden transponder? If you try to move out of range or call for help with your cellphone, might your attempt to flee or the cellphone signal set the device off? Hell, even pushing the unlock button on your key ring now could send the wrong kind of signal, no? But panic is not an option, as it seems you have less than three minutes to decide your best course of action. So what are you going to do?!
What You Have: Your briefcase and pockets contain what a computer engineer might normally have, within reason -- if that includes a Swiss Army knife or Leatherman tool, so be it. Beyond that, your brain is the best tool you've got. So think fast, and ... good luck.