dust rising to the west. Vandam realized he had not been this near the fighting before. The overall impression was one of dirt, panic and confusion. They reported to the command vehicle and were directed to the captured German radio trucks. Field intelligence men were already at work. Prisoners were being interrogated in a small tent, one at a time, while the others waited in the blazing sun. Enemy ordnance experts were examining weapons and vehicles, noting manufacturers! serial numbers. The Y Service was there looking for wavelengths and codes. It was the task of Bogge’s little squad to investigate how much the Germans had been learning in advance about Allied movements. They took a truck each. Like most people in Intelligence, Vandam had a smattering of German. He knew a couple of hundred words, most of them military terms, so that while he could not have told the difference between a love letter and a laundry list, he could read army orders and reports. There was a lot of material to be examined: the captured post was a great prize for Intelligence. Most of the stuff would have to be boxed, transported to Cairo and perused at length by a large team. Today’s job was a preliminary overview. Vandam’s truck was a mess. The Germans had begun to destroy their papers when they realized the battle was lost. Boxes had been emptied and a small fire started, but the damage had been arrested quickly. There was blood on a cardboard folder: someone had died defending his secrets. Vandam went to work. They would have tried to destroy the important papers first, so he began with the half-burned pile. There were many Allied radio signals, intercepted and in some cases decoded. Most of it was routine-most of everything was routine-but as he worked Vandam began to realize that German Intelligence’s wireless interception was picking up an awful lot of useful information. They were better than Vandam had imagined-and Allied wireless security was very bad. At the bottom of the half-burned pile was a book, a novel in English. Vandam frowned. He opened the book and read the first line: “Last night I dreamt I went to Manderley again.” The book was called Rebecca, and it was by Daphne du Maurier. The title was vaguely familiar. Vandam thought THE KEY TO REBECCA 143
his wife might have read it. It seemed to be about a young woman living in an English country house. Vandarn scratched his head. it was, to say the least, pecu~ Iiar readingfor the Afrika Korps. And why was it in English? It might have been taken from a captured English soldier, but Vandam thought that unlikely: in his experience soldiers read pornography, hard-boiled private eye stories and the Bible. Somehow he could not imagine the Desert Rats getting interested in the problems of the mistress of Manderley. No, the book was here for a purpose, What purpose? Vandam could think of only one possibility: it was the basis of a code. A book code was a variation on the one-time pad. A onetime pad had letters and numbers randomly printed in fivecharacter groups. Only two copies of each pad were made: one for the sender and one for the recipient of the signals. Each sheet of the pad was used for one message, then torn off and destroyed. Because each sheet was used only once the code could not be broken. A book code used the pages of a printed book in the same way, except that the sheets were not necessarily destroyed after use. There was one big advantage which a book had over a pad. A pad was unmistakably for the purpose of encipherment, but a book looked quite innocent. In the battlefield this did not matter; but it did matter to an agent behind enemy lines. This might also explain why the book was in English. German soldiers signaling to one another would use a book in German, if they used a book at all, but a spy in British territory would need to carry a book in English. Vandam examined the book more closely. The price had been written in pencil on the endpaper, then rubbed out with an eraser. That might mean the book had been bought second-hand. Vandarn held it up to the light, trying to read the impression the pencil had made in the paper. He made out the number 50, followed by some letters. Was it eic? It might be erc, or esc. It was esc, he realized-fifty escudos. The book had been bought in Portugal. Portugal was neutral territory, with both German and British embassies, and it was a hive of low-level espionage. 144 Ken Follett