The Hardy Boys/Nancy Drew Mysteries

The Hardy Boys (Shaun Cassidy, Parker Stevenson) open a third season on a down note: Joe's fiancée is killed in a hit-and-run auto accident shortly before their wedding, setting him on a reckless trail of vengeance. First of two parts.

 In London, a group of former secret service agents plan the biggest robbery in Britain's history. Their target is the crown jewels.

A kidnapper known as the Scorpion threatens a Senator on the eve of his departure for Puerto Rico, so Joe goes along as his daughter's bodyguard while Frank tries to discover whether the kidnapper's attractive daughter is involved in the plot.

At a detectives' convention, Nancy, Joe and Frank encounter intrigue while solving the disappearance of some sleuths.

While wind surfing in Hawaii, Frank risks his life in a futile attempt to save a champion swimmer who mysteriously disappears into the surf. 

The boys' father disappears, sparking a search that involves them with espionage, a graveyard and a haunted house. 

Hunting for what may be a UFO, the boys stumble upon a mansion wherein rooms change scale and floors disappear. 

While Joe Hardy is making his singing debut at a disco, he and his brother, Frank, become involved in a record tape piracy case.