Glancing at the heads-up overlay on the drop-down LCD, I could see him streaking up behind us: $80,000, pucker red Mercedes SUV sliding dangerously between lanes, forcing other drivers to brake and swerve to avoid collision.

"We've got a live one," I said to Jake, in the passenger seat. "About one click back, five o'clock currently... but he's all over the place."

Jake thumbed open the glove box, then hit a small button blended to look like part of the inner wall. With a light whir the box dropped back into the dash a few inches and a second display tongued out, faced by a small alphanumeric keyboard and mini-joystick. The joystick was capped with a tiny red button.

Jake and I had concocted this vigilante weapon last summer, on a house hunting trip Ania and I had taken to Toronto. The programming was fairly simple, though we'd underestimated the computational power necessary for continuous yet highly accurate trajectory calculation at freeway speeds. We got it right on the second attempt, and there was currently more computational power in this car than in most university labs. The entire project was finished in less than a month, and offered an excuse to purchase welding gear. The modifications to the car's chassis and power systems were cake... the hardest part was actually making the string of connections required to lay hands on an industrial cutting mini-laser anonymously.

The heads up display was blinking at me. "Estimated pass-by in 15 seconds."

Jake reeled out a string of commands on the keyboard, and the laser dropped into place beneath us and rolled on its mounting tracks to the left side of the car's underbody. A satisfying thunk indicated it had auto-mounted into firing position.

"What do you think? 'I'm A Jackass?' 'Fuckwit On Board?'" He wiggled the joystick, biting his lower lip in concentration. He had the fun job tonight.

As the SUV roared up on us, I could see the rosary swinging from its rearview. "Use what we hit the Jesusfish guy with last week!"

The heads up locked and began beeping off seconds until maximal proximity. Jake inched the joystick with slow deliberation, tapping in the command string with his free hand.

"4, 3..."

"I've got him."

"1!"

Jake lightly pressed the joystick's red button and the laser sprang to life. The SUV's driver side panels flamed and smoked in a swift flash of burning car paint and melting metal. It was all over in slightly less than two seconds.

"Perfect!"

The command console slid back into its hidden spot in the dash. We felt the laser return to its hiding box beneath our feet.

We paced the guy for a moment, just long enough to admire our handiwork: "Jesus Doesn't Drive Like You" deeply charred into the side of his vehicle, in a crisp, biblical, stone tablet font.