Original Airdate: October 20, 1965
A fellow space traveler from Earth, Jimmy Hapgood, happens to land on the planet where the Robinsons are stranded. They help him repair his ship and John and Maureen ask Jimmy to take Will and Penny back to Earth. Smith, however, has other plans.
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The Robinsons try to persuade a long-stranded astronaut, James Hapgood, to take Will and Penny back to Earth. He refuses, but has a change of heart after a near tragedy befalls Penny.