Former Detective Superintendent and now prison inmate, John Brace, wants to talk to Detective Inspector Vera Stanhope. As Vera was instrumental in putting him into prison for his involvement with the death of a gamekeeper, she is intrigued and a little suspicious when she goes to see him. He wants a trade-off; he will tell her what happened to Robbie Marshall who disappeared twenty years ago with a host of suspicious deals attributed to him, if Vera will keep an eye on his daughter and grandchildren. Brace's corrupt dealings have enabled him to support them financially.
When Vera follows up his lead she finds two bodies. These take her back in time to when her father was alive and very much one of the buddies of John Brace, Robbie Marshall and the mysterious “Prof”: the Gang of Four. All clues lead back to The Seagull, an upmarket nightclub that functioned in the nineties.
Vera resists believing that her father, Hector, is somehow involved but is too honest a cop not to consider the possibility. She has always known that he flirted with illegality, particularly if it relates to his precious birds' eggs.