Star Trek - The Original Series, Episode 26: The Devil In the Dark [VHS]
There's an emergency on Janus VI, a seemingly uninhabited planet rich in  metals and rare minerals crucial to Federation operations.  There's a lot of money to be made by the mining contractor involved, but  there's a swift-moving, unseen monster roaming the  snaky tunnels of Janus's interior, turning miners into acid-drenched goo.  Fifty men have died, and it's up to theEnterpriseto find the alien culprit and defuse the lynch-mob mentality spreading among the paranoid miners. Captain Kirk (William Shatner), Mr. Spock (Leonard Nimoy), and  Dr. McCoy (DeForest Kelley) beam down to initiate the  detective work, leading Spock to quickly conclude that the thousands of  silicone balls mysteriously strewn about the planet's deepest caves might  have something to do with the reasons behind the atrocities. Written by  series guru Gene L. Coon and directed by mainstay Joseph Pevney (who  alternated directorial chores with Marc Daniels during the show's second  season), "The Devil in the Dark" is a breathlessly paced episode reflecting a delightful variety of cross-genre influences--Westerns, creature features,  gritty noir. Add one of the most effective and moving instances of theEnterprise's search for new life onStar Trek(plus McCoy's  infamous complaint, "I'm a doctor, not a bricklayer"), and this is a memorable program indeed.--Tom Keogh