Kol was a Klingon male who worked as a spy for the Empire. Kol infiltrated the Federation, and posed as Elliot Tindall, a deceased scientist, going so far as to marry a Human, Luisa. In 2286, the medication that allowed Kol to act like a human began failing him, and he started to suffer mood-swings. During this period, Kol's scientific work led to him working aboard the USS Enterprise-A. While aboard the ship, Kol tried to beam aboard the IKS Alliance in order to obtain a new supply of medicine, but was stopped by the Enterprise's crew. He was then interrogated by Spock, and revealed that he was indeed a Klingon spy, confirming Spock's suspicions. (TOS novel: Timetrap)