1944: Helen Stokes, codename Claudette, is parachuted into France by the SOE. When her Paris cell is betrayed, only the action of Drew Kingsley, her senior instructor, gets her home to England. Her accusations of treachery lead to her being labelled a hysterical spinster and she is summarily dismissed. Using her training to evade discovery by the traitor she knows exists, Helen disappears.
1953: Helen, now Peggy Palmer is certain there is corruption in the allocation of contracts for London’s rebuilding. Appalled that everything she fought for is being debased, she writes anonymously to Drew, now Sir Andrew Kingsley. Bored by his Whitehall job, Drew believes Helen/Claudette wrote the letter and finds her. Without telling her, he recruits ex SOE agents to help bring the fraud to light.
Peggy finds herself forced to help, but she fears the traitor now knows who and where she is. Soon she finds those fears are well founded.