The Earthlings become involved in an underground resistance in the giant civilization.

Barry and Fitzhugh are captured by giant Gypsies.

A giant escaping convict takes the Spindrift but then wanders into quicksand, endangering everyone.

The Earthlings try to salvage radium from a clock but find themselves at the mercy of giant scientists using a sound detector to home in on them.

Barry is strick by appendicitis and the Earthlings have no choice but to turn to a giant doctor for assistance.

Mark falls for an attractive Earth girl - the survivor of a previous space flight.

The Earthlings become involved with an insane giant scientist who has infra-red goggles he can use to find them whenever he wants.

Fitzhugh pretends to be an elf to entertain two orphan children, but things turn deadly when it's revealed that traditionally the children sacrifice the elf to make a wish come true.

Mark is roped into helping two giant scientists build a spaceship that can return them all to Earth.

A giant boy-genius comes up with a pill that can enlarge an Earthling to Giant-size.

The Earthlings come to the aid of a giant magician.

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

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

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

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

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

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

A friendly Giant has a teleport device that can send the Spindrift crew back to Earth, but the SID use the whole thing as a trap.

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.