Inspector Kobick of the SID involves the Earthlings in a plan to track down counterfeiters.

The Earthlings become involved in a scientist's scheme to build an indestructible android.

The Earthlings must play a game of real-life chess with a demented giant industrialist.

Steve is turned into a raving paranoid by exposure to mushroom spores, and cuts a deal with Inspector Kobick to betray his crewmates.

The Earthlings aid a giant trumpet player against crooks.

Valerie is forced to act as a toy ballerina in a giant's scheme to kill his rich uncle.

When Chipper is injured by a giant dog, Barry and the others must turn to a giant veterinarian and his sadistic son for assistance.

Fitzhugh is captured by the owner of a wax museum who is involved in a stolen-diamond racket.

A giant scientist performs cloning experiments on the Earthlings.

Two time travellers from 5477 come to the Land of the Giants to conquer Earth.

Barry and Valerie are carried off in a balloon to a distant land ruled by a malevolent dictator.

Fitzhugh and Steve accidentally return to Earth in a space-time pod but end up in 1900 and must deal with hostile villagers.

The Earthlings become involved with a superstitious Irish Giant who believes they're leprechauns.

While working with a helpful Giant scientist, the Earthlings are subjected to radiation which causes strange hallucinations.

An alien piper, claiming to be the Pied Piper of Hamlin, brings his act to the Land of the Giants.

The Earthlings become involved in the politics of a secret underground city.

Mark is framed for the murder of two Giants and begins acting suspiciously, turning his crewmates against him.

The Earthlings become involved in a sabotage scheme to destroy the nearby city.

A sadistic child unleashes his mechanical toys on the hapless Earthlings.

The Earthlings aid an injured puppeteer by pretending to be his dancing puppets, but the owner soon suspects they are involved and prepares to capture them for the reward.

Using a device stolen from time-travelling researchers, Steve and Dan return to the day of the Spindrift's launch and try to alter history and stop the ill-fated flight.