First Season Episodes - The Keeper (part 1) (episode 16)

An alien animal collector threatens to imprison Penny and Will in his intergalactic zoo.

While Dr. Smith, Will and the Robot work on an irrigation ditch, Smith suddenly falls into a trance and marches off. Will follows him to three strange cages. Smith walks into one and then a beast appears and starts to batter the door. Terrified, Will runs back to the Jupiter 2 to tell his father and Don, who follow him back towards the cages. 

Meanwhile, the Keeper, a tall alien with a staff, appears at the cage. He angles his staff at the beast, causing it and the Keeper to dematerialize. The Robot explains that the cages adapt themselves to animals drawn to it by some strange sonar receiver. Suddenly, the Keeper appears, and after giving Maureen some flowers that have sprouted from his staff, he explains that he collects animals from across the universe. The Keeper approaches Don and Judy and tries to persuade them to become his specimens. They refuse. When they relate what happened over dinner, Smith schemes to force the Keeper to fly them back to Earth, but John will not hear of it. 

At his spaceship, the Keeper's leader gives him permission to try to capture two of the Earthlings. The Keeper then lures Will and Penny to his ship. Suddenly, Smith, who has responded to the Keeper's staff, appears and accidentally bumps into him, causing the staff to fall and momentarily dim. The spell broken, Will and Penny run back to the Jupiter 2, where John and Don lock them up to keep them from being drawn away again by the staff's power. Will amuses himself in his cabin by fashioning a sling shot.. The Keeper entrances the children, and Will tricks the Robot into opening the door. 

Discovering the children are gone, John, Don and Maureen use Smith to lead them to the Keeper's ship. There, John demands the return of his children, but his laser gun is ineffective against the alien. Will passes his slingshot to Don to shoot the light at the top of the Keeper's staff. The staff goes dead and the children are freed. The Keeper decides to pack up and leave, but that night, Smith accidentally lets all of the Keeper's animals loose while trying to hijack his ship.

Bill Mumy on Working with Michael Rennie

If you talk about Lost in Space guest casts, there was no one better than Michael Rennie! The Day the Earth Stood Still is my favorite sci fi film, so... how cool to have worked with Michael Rennie for the only 2 parter we ever filmed.

It was a good, "traditional" sci fi episode... classic premise... he played a very likable villain. An honorable character in his own way.

Michael Rennie - The Keeper

Michael Rennie, sci-fi icon from The Day the Earth Stood Still, appeared in LIS's only 2-part episode, as well as the pilot for The Time Tunnel.

It was also a bit of a reunion for Jonathan Harris, who had worked with Rennie in the 1959-65 TV series The Third Man.

Filming