Barnaby and Jones investigate the shooting of a blackmailer, Martin Barrett. But he had so many victims, they are spoiled for choice for a suspect. Then one of his victims, Sir John Waverley, gets another demand. The trail leads them to the seaside and diving for treasure on an uncataloged wreck.
Elenco: John Nettles , Jane Wymark , Barry Jackson , Laura Howard , Neil Dudgeon , Jason Hughes , Fiona Dolman , Tamzin Malleson , Kirsty Dillon , Daniel Casey , John Hopkins , Nick Hendrix , Gwilym Lee .