May 1951. Celebration is in the air with the Festival of Britain and for the first time in years the mood is one of hope rather than hurt. For Detective Constable Faye Smith, London is not as safe as it seems. The criminal underworld is gaining strength, enjoying a lively existence below the surface. Then two bodies are found in the war-time shelters, a man and a woman. Who are they? What's their story? Why were they murdered and how did they end up in the shelters? Meanwhile, Ellie Peveril is busy with a celebration of a different kind. Ellie does all she can to support her friend but has her own worries, with ex-fiancé Patrick Havistock looming in the shadows. Faye, keen to unravel the mystery of the double murder, finds herself tangled up in crimes that stretch far beyond a simple killing. Faye and Ellie must face their toughest case yet as their lives change, irrevocably, for the future.