When I came to write Atonement, my father's stories, with automatic ease, dictated the structure; after I finished the opening section, set in 1935, Dunkirk would have to be followed by the reconstruction of a 1940 London hospital. It is an eerie, intrusive matter, inserting imaginary characters into actual historical events. A certain freedom is suddenly compromised; as one crosses and re-crosses the lines between fantasy and the historical record, one feels a weighty obligation to strict accuracy. In writing about wartime especially, it seems like a form of respect for the suffering of a generation wrenched from their ordinary lives to be conscripted into a nightmare.
The writer of a historical novel may resent his dependence on the written record, on memoirs and eyewitness accounts, in other words on other writers, but there is no escape: Dunkirk or a wartime hospital can be novelistically realised, but they cannot be re-invented. I was particularly fascinated by the telling detail, or the visually rich episode that projected unspoken emotion. In the Dunkirk histories I found an account of a French cavalry officer walking down a line of horses, shooting each one in turn through the head. The idea was to prevent anything useful falling into the hands of the advancing Germans. Strangely, and for exactly the same reason, near Dunkirk beach, a padre helped by a few soldiers burned a pile of King James bibles. I included my father's story of the near-lynching of an RAF clerk, blamed by furious soldiers for the lack of air support during the retreat. Though I placed my imagined characters in front of these scenes, it was enormously important to me that they actually happened.