Rebus investigates when an old friend, DI Jack Morton, is shot during an undercover operation at a pharmaceuticals factory which has become a hub for cocaine dealing and gun-running by a well-known mobster and his latest team of upstart thugs.

Rebus is forced to juggle two complex cases when an old friend approaches him to trace her son, who has disappeared, and a former colleague is killed in a freak accident, which asks the question - did he kill himself or was he murdered?