In the heat of an Australian summer, Inspector Scobie Malone of the New South Wales police finds the body of a promising informer, Scungy Grime, floating face down in his family's backyard swimming pool. Scobie is investigating Sydney's major drug-dealing operation, and Grime's murder is a clear warning. Malone's family is put under police protection—a nightmare for Scobie, who had always been able to separate his professional obligations from his home life. But Scobie is determined not to be frightened off the job and leads the search for the murderer.

Scungy Grime turns out to be only the first victim of an innovative killer who injects his victims with curare. The trail leads in many directions: to Grime's former boss, retired big-time criminal Jack Aldwych; to Aldwych's son, Junior, who is using his father's ill-gotten fortune to build a legitimate business empire; to Junior's unlikely girlfriend, Janis, a tough-nut social worker who counsels drug addicts; and to the original target, Sydney's drug king, Danny Pelong, who is annoyed because an unknown newcomer is muscling in on his patch.

The case before Malone is baffling. Worried as he is for his family's safety, distracted by his partner's troublesome love life, with the bite of economic recession casting gloom, this dark summer seems endless—until a vital clue appears, and the case begins to unravel.