Early in 1943, Germany changed its weather code books, depriving the British cryptanalysts of their only means of breaking the particularly diabolical version of Enigma used by the U-boats. Shortly before this blackout, three convoys had left New York carrying not just cargo but civilian passengers, and begun heading toward the area patrolled by the submarine wolf packs. With just four days to break a code that took ten months the first time, the codebreakers at Bletchley Park send for Tom Jericho, holed up at Cambridge recovering from a nervous breakdown. Since he had gotten them into Shark the first time, they hope he can do it again.
But Jericho has other things on his mind. The Bletchley worker with whom he had been having an affair has vanished after relieving her office of several undeciphered cryptograms. He begins a search for her, aided and abetted by her roommate Hester, who was drafted to Bletchley after winning a crossword competition - then made a glorified file clerk while several of the men she beat did the actual codebreaking. Finding Claire, and her reason for stealing the cryptograms, provides her with a chance to do some real work. Investigating the theft, Jericho begins to suspect that there is a traitor somewhere in Bletchley Park. Which would certainly explain why the police are swarming all over the countryside....
The bonus of Enigma is that there’s not one race against time but two: finding Claire and the traitor, and finding a way to break Shark before the convoys get within range of the U-boats. It’s a testament to the quality of the writing that I was still able to enjoy the suspense despite having a. seen the movie and b. read a non-fiction book about Enigma last semester. I don’t usually care for twentieth-century history, but this setting appealed to me, puzzles and code-breaking being right up my alley (yes, I’m one of those newspaper-sudoku tragics). The fictional characters and events were neatly fitted around real events such as the codebreaking blackout and the fate of the three convoys, and the convoluted workings of the Enigma machines were clearly explained. And it has one of my favourite kinds of endings: no loose ends, but that one little twist that keeps everything from being perfectly tidy.
My only real disappointment reading this book was that my favourite line from the movie was actually a screenwriter’s improvement on a less snappy original (I’d been looking forward to meeting it again). In the film, Kate Winslet’s Hester, informed by her slimy boss that, without her glasses, she didn’t look half bad, replied ‘Really? You know, without my glasses, neither do you.’ Being short-sighted and frequently bespectacled myself, I have filed that one away for future reference.