The death of a popular pleasure boat captain saddens the locals in a busy holiday town; but they are even more distraught on hearing that he may have been murdered. D.C.I.Baxter and D.Sergeant Landing are sent to investigate the case and are soon caught up in a dramatic chase, as a host of incidents point to a purge of deaths of all the passenger who were stranded on the rocks a few days earlier. Baxter and Landing find themselves two steps behind in their desperate attempt to stop the mayhem...................