Lost in Space: The Galaxy Gift on AllMovie

In the final episode of Lost in Space's second season, Penny (Angela Cartwright) saves the life of an alien named Arcon (John Carradine), who entrusts her with a valuable amulet. Not long afterward, a trio of sinster space thugs show up, demanding that Penny give up the amulet, or else the rest of her family will die a horrible death. Making Penny's choice all the more difficult is the fact that the amulet holds the power to destroy the universe. (Trivia note: the costumes worn by the villainous "Saticons" were previously seen in the episode "Wreck of the Robot").