When sole survivor of an RAF bomber that crashes in the mountains of central France in the winter of 1941, former Oxford student Philip Lawless is rescued by two sisters, Séverine and Thérèse Chevalier who live in a remote farmhouse that was once a fortified outpost of the mediaeval Knights Hospitalers from whom the sisters' family is descended. Against orders, Lawless repays his debt by remaining to work on the farm and in time falls in love with and marries Thérèse. He joins Séverine in the French Resistance, takes part in its operations and gains the respect of her uncle Alexandre, scholar and Resistance chief, and Alexandre's lover, the seductive Justine Lamphier. The German invasion of Unoccupied France in 1942 forces Lawless to leave his wife and newborn son and escape back to England through Spain carrying secret documents from Alexandre for British Intelligence. He becomes a pilot in a bomber squadron heavily engaged in costly raids on Germany. Returning from his final mission in 1944 he is shot down and severely injured. Three years later he awakes from a coma, physically fit but remembering nothing and no one of his War years. Lawless resumes his studies in Oxford with his former tutor and lover and now a College Principal, Winifred Smallwood. He marries again and in time becomes an eminent Professor of Mediaeval languages, still unaware of his forgotten family and comrades in France and the RAF. Then a chance meeting and a piece of music change everything.