Bruce Hyde's portrayal of Lieutenant Kevin Thomas Riley made an insignificant bit part into one of the most memorable minor characters from the original Star Trek. In The Naked Time (TOS), he proclaims himself Captain, locks himself in engineering, and shuts down the engines, endangering the USS Enterprise. In The Conscience of the King (TOS), it's revealed that, along with Captain Kirk, he's one of the survivors of the massacre on Tarsus IV. The latter role was originally for a character named Lieutenant Robert Daiken, but when Hyde was cast, the name was changed to the character he played in The Naked Time.