Frozen World
"The Naked Time"
Spock and a crewman land on a frozen planet whose inhabitants died mysteriously, overcome by some kind of space madness. As Spock prepares to beam up to Enterprise, the crewman, in a moment of carelessness, exposes his hand to the environment and becomes afflicted with a strange virus. It not only effects [sic] him, but threatens the entire crew as well!
