The boy slept beside the calculating engine.

Rory walked into the room. The sleeper, Ben Kamen, lay slumped over his desk, bulky volumes of physics journals opened around him, pages of foolscap covered with his spidery Germanic handwriting.

Crammed full of the components of the Analyser, the room smelled sharply of electricity, an ozone tang that reminded Rory of the wind off the Irish Sea. But this was Cambridge, Massachusetts, and he was in MIT, an oasis of immense concrete buildings. He was a long way indeed from Ireland. Nobody knew he was here, what he was doing. His heart hammered, but his senses were clear, and he seemed to see every detail of the cluttered, brightly lit room.

He turned away from Ben to the bank of electromechanical equipment that dominated the room. The Differential Analyser was an engine for thinking. There were tables like draughtsmen's workbenches, and banks of gears and wheels, rods and levers. This clattering machine modelled the world in the spinning of these wheels, the engaging of those gears. Earlier in the day Rory had fed it the data it needed, carefully tracing curves on the input tables, and manually calculating and calibrating the gear ratios. He ripped off a print of its results. The Godel solutions were ready.

And Ben Kamen was ready too. Sleeping, Ben looked very young, younger than his twenty-five years. There was nothing about him to suggest his origin, as an Austrian Jew. One hand still held his fountain pen; the other was folded under his left cheek. His features were small, his skin pale.

Rory looked over what was assembled here: the brooding machine, the boy.