In the science fiction TV series Star Trek (1966-1969), the characters of Captain James T. Kirk and his Vulcan science officer Mr. Spock share an unusually close friendship, although both characters have relationships and sexual liaisons with women. Almost from the beginning, fans noticed the loving nature of the relationship. A few fan writers started speculating about the possibility of a sexual relationship between Kirk and Spock. The Kirk/Spock phenomenon eventually took on a life of its own, and became one of the driving forces in Star Trek fanzines during their heyday. The relationship between Kirk and Spock is a very loyal one and when Kirk believes Spock has been disloyal to him in the Menagerie he shows great pain.