Enigma

Acknowledgements

I OWE A debt of gratitude to all those former employees of Bletchley Park who spoke to me about their wartime experiences. In particular, I would like to thank Sir Harry Hinsley (Naval Section, Hut 4), Margaret Macintyre and Jane Parkinson (Hut 6 Decoding Room), the late Sir Stuart Milner-Barry (former head of Hut 6), Joan Murray (Hut 8) and Alan Stripp (Japanese ciphers).

Roger Bristow, Tony Sale and their colleagues at the Bletchley Park Trust answered my questions with great patience and allowed me to wander about the site at will.

None of these kind people bears any responsibility for the contents of this book, which is a work of the imagination, not of reference.

For those readers who would like the facts on which this novel is based, I strongly recommend Top Secret Ultra by Peter Calvocoressi (London, 1980), Codebreakers edited by F. H. Hinsley and Alan Stripp (Oxford, 1993), Seizing the Enigma by David Kahn (Boston, USA, 1991), The Enigma Symposium by Hugh Skillen (Middlesex, two volumes, 1992 and 1994), The Hut 6 Story by Gordon Welchman (New York, 1982) and GC//Q by Nigel West (London, 1986).

Details of the action in the North Atlantic are drawn from the original, decoded signals of the U-boats, held at the Public Record Office in London, and also from Convoy by Martin Middlebrook (London, 1976) and The Critical Convoy Battles of March 1943 by Jiirgen Rohwer (English translation, London, 1977).

Finally, I would like to record my special thanks to Sue Freestone and David Rosenthal, neither of whom ever lost faith in Enigma, even on those occasions when it was a mystery to its author.

Robert Harris

June 1995

The End