Enigma

never paid much attention to security—shouting about Hut 8 in the station buffet, demanding to know what he did, trying to tell him what she did. A dare? Again, possible. She was capable of anything. But that hole in the floorboards, the cool deliberation of it, drew his gaze and mocked his advocacy.
    A sound, a footstep downstairs, dragged him out of his reverie and made him jump to his feet.
    He said, 'Hello?' in a loud voice that suggested more courage than he felt. He cleared his throat. 'Hello?' he repeated. And then he heard another nose, definitely a footstep, and definitely outside now, and a charge of adrenaline snapped in. He moved quickly to the bedroom door and turned the light off, so that the only illumination in the cottage came from the sitting room. Now, if anyone came up the stairs, he would be able to see their silhouette, while remaining hidden. But nothing happened. Perhaps they were trying to come round the back? He felt horribly vulnerable. He moved cautiously down the stairs, flinching at every creak. A blast of cold air struck him.
    The front door was wide open.
    He threw himself down the last half-dozen steps and ran outside, just in time to see the red rear light of a bicycle shoot out of the track and vanish down the lane.
    He set off in pursuit but gave up after twenty paces. He didn't stand a chance of catching the cyclist.
    There was a heavy frost. In every direction the ground shone a dull and luminous blue. The branches of the bare trees were raised against the sky like blood vessels. In the glittering ice, two sets of tyre-tracks were imprinted: incoming and outgoing. He followed them back to the door, where they ended in a series of sharp footprints.
    Sharp, large, male footprints.
    Jericho looked at them for half a minute, shivering in his shirtsleeves. An owl shrieked in the nearby copse and it seemed to him that its call had the rhythm of Morse: dee-dee-dee-dah, dee-dee-dee-dah.
    He hurried back into the cottage.
    Upstairs, he rolled the intercepts very tightly into a cylinder. He used his teeth to tear a small hole in the lining of his overcoat and pushed the signals into it. Then he quickly screwed down the floorboards and replaced the rug. He put on his jacket and coat, turned off the lights, locked the door, replaced the key.
    His bicycle added a third set of impressions in the frost.
    At the entrance to the lane he stopped and looked back at the darkened cottage. He had a strong sensation—foolish, he told himself—that he was being watched. He glanced around. A gust of wind stirred in the trees; in the blackthorn hedge beside him, icicles clinked and chimed.
    Jericho shivered again, remounted the bike and pointed it down the hill, towards the south, towards Orion and Procyon, and to Hydra, which hung suspended in the night sky above Bletchley Park like a knife.

Enigma
    FOUR

    KISS
    KISS: the coincidence of two different cryptograms, each transmitted in a different cipher, yet each containing the same original plaintext, the solution of one thereby leading to the solution of the other.
    A Lexicon of Cryptography ("Most Secret', Bletchley Park, 1943)

1

    HE DOESN'T KNOW what wakes him—some faint sound, some movement in the air that hooks him in the depths of his dreams and hauls him to the surface.
    At first his darkened room seems entirely normal—the familiar jet-black spar of the low oak beam, the smooth grey plains of wall and ceiling—but then he realises that a faint light is rising from the foot of his bed.
    'Claire?' he says, propping himself up. 'Darling?'
    'It's all right, darling. Go on back to sleep.'
    'What on earth are you doing?'
    'I'm just going through your things.'
    'You're. . . what?'
    His hand jumbles across the bedside table and switches on the lamp. His Waralarm shows him it is half past three.
    'That's better,' she says, and she turns off the blackout torch. 'Useless thing, anyway.'
    And she is doing exactly what she says. She is naked except for his shirt, she is kneeling, and she is going through his wallet. She removes a couple of one-pound notes, turns the wallet inside out and shakes it.
    'No photographs?'she says.
    'You haven't given me one yet.'
    'Tom Jericho,' she smiles, replacing the money, I do declare, you 're becoming almost smooth.'
    She checks the pockets of his jacket, his trousers then shuffles on her knees across to his chest of drawers. He laces his hands behind his head and leans back against the iron bedstead and watches