Pon farr, a physiological response introduced in "Amok Time" that impelled Vulcans to "have sex or die", is a device used in some stories such as "The Ring of Soshern", a pre-1976 fan fiction where Kirk and Spock are marooned on an uncharted planet. However, other writers suggest that it is biologically impossible for a male to consummate pon farr with another male. Furthermore, in the "Original Series", it is clearly stated that Vulcans are legally bound with their mate as children. They may neglect the relationship in future years but pon farr compels them to consummate the marriage at the appropriate time. Vulcans must mate or die "trying". However, in "Amok Time", Spock finds that a substitute to giving in to pon farr is to kill another, and thus Spock's pon farr imperative ends after he kills.