Cryptonomicon

Working quickly, Waterhouse sets two single-edged razor blades into it, the blades dangerously upward-facing, parallel and somewhat less than an inch apart. He holds them in place for a few moments while the frigid metal of the safe sucks the heat out of that glue and makes it hard again. He has employed a pair of toothpicks as spacers to make sure that the blunt backs of the blades do not actually touch the door of the safe; he does not want an electrical connection between them.

He solders a wire onto each of the razor blades and runs the wires across the altar toward the radio. Then he takes a little chunk of carbon and lays it across the two blades, forming a bridge between them.

He tears open the back of the radio and does a bit of rewiring. Most of the rig is already set up the way he needs it; basically he's looking for something that will convert electrical impulses into sound and pump that sound into the headphones, which is what a radio does. But the source of the signal is no longer a transmitter on a U-boat but rather the current flowing up one of Waterhouse's wires, into the left razor blade, across the carbon bridge, into the right razor blade, and back down the other wire.

Getting this hooked up the way he wants it takes some doing. When he blunders down a blind alley and gets frustrated, he will go over and twiddle the antenna for a while, pretending to zero in on a U-boat. Then an idea will occur to him and he will go back to work.

Sometime around dawn, he hears a squeal from the headphones: a pair of Bakelite cups bridged by a contraption that looks like a primitive surgical device, hooked up to the radio by a twisted pair of black and red wires. He turns the volume down and claps the phones over his head.

He reaches out and lays one fingertip on the safe, and hears a painful thud in his ears. He slides the fingertip over the surface of the cold metal and hears a rasping sound. Any vibrations cause the bridge of carbon to tremble on the razor blades, making and breaking the electrical connection, modulating the electrical current. The blades and the carbon are a microphone, and the microphone works--almost too well.

He takes his hand off the safe and just sits there and listens for a while. He can hear the footfalls of skerries going through the detachment's rations. He can hear the impact of waves on the shore, miles away, and the thump of the Taxi's bald tires on chuckholes out on the Road. Sounds like the Taxi has a little alignment problem! He can hear the scrub, scrub of Margaret cleaning the floor of the kitchen, and some minor arrhythmias in the heartbeats of the enlisted men, and the boom of glaciers calving on the coast of Iceland, and the squirrely drone of hastily machined propellers on approaching convoy ships. Lawrence Pritchard Waterhouse is plugged into the Universe in a way that exceeds even what Bletchley Park has to offer.

The center of that particular universe is the Safe from U-553, and its axis passes up through the center of the Dial, and now Waterhouse has his hand on it. He turns the volume way down before he touches any thing so that he won't blow his eardrums out. The Dial spins heavily but easily, as if mounted on gas bearings. Still, there is mechanical friction in there which is not perceptible to Waterhouse's admittedly frozen fingers but which comes through in his earphones like a rockslide.

When the tumblers move, it sounds like Waterhouse is shooting the main bolt on the Gate of Hell. It takes him a little while, and a few more false starts, to get his bearings; he doesn't know how many numbers are in the combination, or which way he should turn the dial to begin with. But with experimentation, some patterns begin to show through, and eventually he works out the following combination:

23 right--37 left--7 right--31 left--13 right and then there's a really meaty click and he knows in his marrow that he can take off the headphones. He spins a little wheel that is mounted on the front of the safe adjacent to the dial. This withdraws the radial dogs that have been holding the door shut. He hauls the door up, careful not to slash his hand on the twin razors, and looks into the safe.

His feeling of disappointment that accompanies this action has nothing to do with the contents of the safe. He is disappointed because he has solved the problem, and has gone back to the baseline state of boredom and low-level irritation that always comes over him when he's not doing something that inherently needs to be done, like picking a lock or breaking a code.

He sticks his arm all the way down to the bottom of the safe and finds a metal object about the size of a hot dog bun. He knew it would be there because, like children investigating wrapped presents in the days before Christmas, they have been tilting the safe this way and that, and when they did, they heard something sliding from one end to the other--going tink, tonk, tink, tonk–-and wondered what it was.