Original Airdate: November 17, 1965
An alien probe precedes the arrival of an alien race of beings called the Taurons. The Robinsons believe these aliens are peaceful and looking to settle on Priplanus. Dr. Smith, however, thinks they are the first arrivals of an enormous invading army.
Watch Lost In Space The Sky Is Falling Online
The Robinsons confront their mistrust of an alien family that has beamed in from space. Unable to understand their language, they fear for Will's safety when he and the little alien boy disappear.