Enigma

hands and lowered her head and he did the same. Footsteps came halfway up the aisle behind them, stopped, and then resumed slowly on tiptoe. Jericho glanced surreptitiously to his left in time to see the elderly priest bending to retrieve his vestment.
    'Sorry to interrupt your prayers,' whispered the vicar. He gave Hester a little wave and a nod. 'Hello there. So sorry. I'll leave you to God.'
    They listened to his fussy tread fading towards the back of the church. The door was tugged shut. The latch fell with a crash. Jericho sat back on the pew and laid his hand over his heart and swore he could feel it beating through four layers of clothing. He looked at Hester—I'll leave you to God?' he repeated—and she smiled. The change it wrought in her was remarkable. Her eyes shone, the hardness in her face softened—and for the first time he briefly glimpsed the reason why she and Claire might have been friends.
    Jericho contemplated the stained-glass window above the altar and made a steeple of his fingers. 'So what exactly are we to make of this? That Claire must have stolen the entire contents of the file? No -' he contradicted himself immediately '—no, that can't be right, can it, because what she had in her room were the original cryptograms, not the decodes . . ,?'
    'Precisely,' said Hester. 'There was a typewritten slip in the Registry file which the clerk showed me—words to the effect that the enclosed serial numbers had been reclassified and withdrawn, and that all enquires should be addressed to the office of the Director-General.'
    'The Director-General! Are you sure?'
    'I can read, Mr Jericho.'
    'What was the date on the slip?'
    'March the 4th.'
    Jericho massaged his forehead. It was the oddest thing he'd ever heard. 'What happened after the Registry?'
    'I went back to the hut and wrote my note to you. Delivering that took the rest of my meal break. Then it was a matter of getting back into the Index Room whenever I could. We deep a daily log of all intercepts, made up from the blists. One file for each day.' Once again she rummaged in her bag and withdrew a small index-card with a list of dates and numbers. 'I wasn't sure where to start so I simply went right back to the beginning of the year and worked my way through. Nothing recorded till February the 6th. Only eleven interceptions altogether, four of which came on the final day.'
    'Which was what?'
    'March the 4th. The same day the file was removed from the Registry. What do you make of that?'
    'Nothing. Everything. I'm still trying to imagine what a rear-echelon German signals unit could possibly say that would warrant the removal of its entire file.'
    'The Director-General is who, as a matter of interest?'
    'The chief of the Secret Intelligence Service. “C”. I don't know his real name.' He remembered the man who had presented him with the cheque just before Christmas. A florid face and hairy country tweeds. He had looked more like a farmer than a spy master. 'Your notes,' he said, holding out his hand. 'May I?'
    Reluctantly she handed him the list of interceptions. He held it towards the pale light. It certainly made a bizarre pattern. Following the initial interception, just after noon on 6 February, there had been two days of silence. Then there had been another signal at 1427 hours on the 9th. Then a gap of ten days. Then a broadcast at 1807 on the 20th, and another long gap, followed by a flurry of activity: two signals on 2 March (1639 and 1901), two on the 3rd (1118 and 1727), and finally four signals, in rapid succession, on the night of the 4th. These were the cryptograms he had taken from Claire's room. The broadcasts had begun just two days before his final conversation with Claire at the flooded clay pit. And they had ended a month later, while he was still at Cambridge, less than a week before the Shark blackout.
    There was no shape to it at all.
    He said: 'What Enigma key were they transmitted in? They were enciphered in Enigma, I take it?'
    'In the Index they were catalogued as Vulture.'
    'Vulture?'
    'The standard Wehrmacht Enigma key for the Russian front.'
    'Broken regularly?'
    'Every day. As far as I know.'
    'And the signals—how were they sent? They were, what, just carried on the usual military net?'
    'I don't know, but I'd say almost certainly not.'
    'Why?'
    'There's not enough traffic, for a start. It's too irregular. And the frequency's not one I recognise. It feels to me like something rather more special—a private