Originally aired: December 14, 1969 on ABC
Writer: William Welch
Director: Nathan Juran, Sobey Martin
Show Stars: Don Marshall (Dan Erickson), Deanna Lund (Valerie Ames Scott), Heather Young (I) (Betty Hamilton), Gary Conway (Captain Steve Burton), Stefan Arngrim (Barry Lockridge), Don Matheson (Mark Wilson), Kurt Kasznar (Commander Alexander B. Fitzhugh)
Guest Stars: Nehemiah Persoff (Titus) , Fred Villani (Sentry) , Ron Husmann (Flight Controller) , Clint Ritchie (Andros) , Brian Nash (Boy In Park) , Peter Canon (Slave #1) , Bob Braun (Balloon Vendor)
Production Code: 4710
While stealing firecrackers for the gunpowder, Barry and Valerie take refuge in a giant child's balloon, which is cut loose. Mark and Steve hop in, and the balloon is inexplicably drawn west, against the wind and across the "Sea of Storms". Dan and Fitzhugh can only listen helplessly as the rest of the group are drawn out of range.
They end up in a foreign land ruled by a giant tyrannical king, Titus. Titus has used some kind of tractor beam to draw them to him. He thinks that everyone in the Earthlings' area are their sizes, and finds the contradiction between their size and various Giant-sized items puzzling. He sends back Steve under a deadline to acquire proof of their claim everyone else is giant-sized, holding the other three as hostages.
Steve barely manages to do so, and brings back Dan and Fitzhugh with him. They leave the balloon via parachute before arriving, and blow up Titus' power plant. With the help of a rebelling slave, Andros, the entire group escapes and floats slowly back to their ship and "home".