In March 1949, Eleanor Alderton receives a letter she should not have received. It is written in her husband's hand, dated the 18th of December, 1943 — two months and a fortnight after she was told he died in France. James Alderton was a SOE officer. Eleanor was a Bletchley codebreaker. Between them, they had devised a private signal — a phrase that meant: I am being watched. Do not come looking. Wait.

The phrase is in the letter. She understands it immediately. And the envelope bears a Kent postmark, not a French one. Someone in England sent this letter. Someone who knew. Someone who has been sitting with the truth for six years.

Eleanor writes to the one person she trusts: a Detective Chief Inspector named Robert Delaney. And so begins an investigation that will take Delaney and his unlikely associate, the practical and perceptive Margaret Carroll, to Brittany — to a quiet village on the coast, to a beach where men came home in the dark, and where the residents live with the choices they made during the war.

The House of Alphonse is told entirely through letters, journals, telegrams, and official documents. There is no narrator. There is only the post.