It is 1964, and Chris Nash is 20. His mother is married to Reg, whom Chris thinks is his father. He is, therefore, astonished when she tells him that his real father was a pilot, John Gregson, killed during the Second World War in an accident training Australian air crews. Chris sets out to discover more about the little-known incident. He tracks down his father's only living relative, and visits the site of the crash, near a small church in Bedfordshire.

In flashback, we see what happened to Gregson during the three days before the accident. He conducted his last bombing flight over Germany, and was seduced by an actress named Sarah. He visited his fiancée (Chris' mother), who broke off their engagement; unknown to him she was pregnant with Chris.

To commemorate the airmen who died in the crash, Chris organizes a memorial stone in the Bedfordshire churchyard, and a church service. To his amazement, a surprise guest turns up: an Australian who was the one survivor.

In talking to local people who were involved in the accident, and to his father's former engineer, Chris comes to believe there were seven airmen on the plane, not six as previously believed. And when he locates Sarah, the actress who seduced his father 20 years earlier, she tells him something that plays havoc with the lives of his whole family.