Thanks to a heart transplant, former FBI agent Terry McCaleb is enjoying quiet retirement, renovating the fishing boat he lives on in Los Angeles Harbour. But McCaleb's calm seas turn choppy when a beautiful woman called Graciela Rivers comes visiting his dock. From her McCaleb learns a terrible truth: that the heart beating in his chest belonged to her sister, who was not killed an accident - as he'd been told - but was murdered. The investigation, Graciela tells him, has gone cold. Will he take it up?