Enigma

you were seeing.'
    Skynner knew about her, and Logie had seemed to know as well. What was it he'd called her? The 'arctic blonde'? Perhaps they all knew? Puck, Atwood, Baxter, everybody?
    He had to get out, get away from the smell of her perfume and the sight of her clothes.
    And it was that action that changed everything, for it was only when he stood on the landing, leaning with his back to the wall and his eyes closed, that he realised there was something he'd missed.
    He walked back slowly and deliberately into her room. Silence. He stepped across the threshold and repeated the action. Silence again. He got down on his knees. One of auntie's Kensington rugs covered the floorboards, something oriental, stained, and tastefully threadbare. It was only about two yards square. He rolled it up and laid it on the bed. The wooden planks which had lain beneath it were bowed with age, worn smooth, fixed down by rust-coloured nails, untouched for two centuries—except in one place, where a shorter length of the old planking, perhaps, eighteen inches long, was secured by four very modern, very shiny screws. He slapped the floor in triumph.
    'Is there any other point to which you would wish to draw my attention, Mr Jericho?'
    'To the curious incident of the creaking floorboard.'
    'But the floorboard didn't creak.'
    'That was the curious incident.'
    In the mess of her bedroom he could see no suitable tool. He went down into the kitchen and found a knife. It had a mother-of-pearl handle with an 'R' engraved on it. Perfect. He almost skipped across the sitting room. The tip of the knife slotted into the head of the screw and the thread turned easily, it came away like a dream. So did the other three. The floorboard lifted up to reveal the horsehair and plaster of the downstairs ceiling. The cavity was about six inches deep. He took off his overcoat and his jacket and rolled up his sleeve. He lay on his side and thrust his hand into the space. To begin with he brought out nothing except handfuls of debris, mostly lumps of old plaster and small pieces of brick, but he kept on working his way around until at last he gave a cry of delight as his hand touched paper.
    He put everything back in its place, more or less. He hung the clothes back up from the beams, piled her underclothes and her scarves back into the drawers and replaced the drawers in the mahogany chest. He heaped the trinkets of jewellery into their leather case and draped others artfully along the shelves, together with her bottles and pots and packets, most of which were empty.
    He did all this mechanically, an automaton.
    He remade the bed, lifting off the rug and smoothing down the eiderdown, throwing the lace cover over it where it settled like a net. Then he sat on the edge of the mattress and surveyed the room. Not bad. Of course, once she began looking for things, then she would know someone had been through it, but at a casual glance it looked the same as before—apart, that is, from the hole in the floor. He didn't know yet what to do about that. It depended on whether or not he replaced the intercepts. He pulled them out from under the bed and examined them again.
    There were four, on standard-size sheets, eight inches by ten. He held one up to the light. It was cheap wartime paper, the sort Bletchley used by the ton. He could practically see a petrified forest in its coarse yellow weave—the shadows of foliage and leaf-stalks, the faint outlines of bark and fern.
    In the top left-hand corner of each signal was the frequency on which it had been transmitted—12260 kilocycles per second—and in the top right its TOI, Time of Interception. The four had been sent in rapid succession on 4 March, just nine days earlier, at roughly twenty-five-minute intervals, beginning at 9.30 p.m. and ending just before midnight. Each consisted of a call sign—ADU—and then about two hundred five-letter groups. That in itself was an important clue. It meant, whatever else they were, they weren't naval: the Kriesgmarine's signals were transmitted in groups of four letters. So they were presumably German Army or Luftwaffe.
    She must have stolen them from Hut 3.
    The enormity of the implications hit Jericho for a second time, winding him like a punch in the stomach. He arranged the intercepts in sequence on her pillow and tried very hard, like a defending King's Counsel, to come up with some innocent explanation. A piece of silly mischief? It was possible. She had certainly