AllMovie

Demented space pirate Admiral Zahrt (Ronald Long) shanghais Will (Billy Mumy), Dr. Smith (Jonathan Harris) and the Robot, forcing the trio to work as his crew. Zahrt needs as many hands as he can get in his never-ending quest to find his mutinous first mate Mr. Christiansen, who had stranded the Admiral on the Robinsons' planet years earlier. Meanwhile, the rest of the Robinsons, along with Don West (Mark Goddard), do what they can to rescue the kidnapped trio (and, incidentally, to remind the viewers that they're still on Lost in Space too).