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.

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

After the Earthlings are inadvertently responsible for two children becoming trapped in a well, they volunteer their servicse to rescue them.

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

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

The Spindrift crew finds a paranoid survivor from Earth...but his suspicions endanger everyone.

The Giants have invented a detector that can home in on Earth-based metals, and Dan puts the entire group at risk due to the surgical pin in his leg.

Kobick uses a captured Chipper as bait in a trap to capture the entire Spindrift crew.

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 deaf boy and his poverty-stricken family.

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

The Earthlings find themselves trapped in an Earth-sized town run by a giant eccentric and his sadistic daughter.

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

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

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 Giants have invented a chemical that forces those exposed to it to tell the truth, and plan to test it on the Earthlings.

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.

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.

A giant scientist performs cloning experiments on the Earthlings.

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 in the politics of a secret underground city.

When a giant hobo is framed for murder, the Earthlings come to his aid.

The Spindrift crew find an amnesiac Earthling, Joe, but it turns out to be a ploy by giant crooks to get hold of the ship's power supply.