Part one of two. The events of 1983, when a mystery in a small fishing town in west Wales led to the discovery of a drug-smuggling ring. The initial puzzle prompted locals to investigate, only to stumble onto something far bigger than anyone could have imagined. The police investigation that followed led rural detectives on their biggest ever case as they unravelled one of Britain's most audacious - and strangest - narcotics conspiracies, involving yachts, speed boats, supercars with hidden panels and mansions with buried treasure