By 2277, Lieutenant Xon was assigned as science officer to the ISS Enterprise, under the command of Admiral Spock. In this year, Xon accompanied Spock, Commander Willard Decker, Ensign Saavik, Solok and Stang to the surface of Deneva for a strategic conference with Starfleet. Xon then assisted the landing party in disarming the assassins and booby traps that had been layed in an attempt to assassinate Spock. In a final act before leaving Deneva, Xon and Saavik killed Commander Decker for his role in the attempted assassination.
In 2287, Xon succeeded Saavik as the Enterprise's first officer when she assumed the captaincy. Later in 2293, he would (presumably) assume command of the Enterprise after Saavik's resignation at the request of Emperor Spock. However, his command would be short-lived as the Enterprise would be destroyed during the downfall of the Terran Empire at the hands of the Klingon-Cardassian Alliance. (TOS - Mirror Universe novel: The Sorrows of Empire)
|ISS Enterprise (NCC-1701) personnel|
|Robert April • Phillip Boyce • Christine Chapel • Pavel Chekov • J. Mia Colt • Robert D'Amato • Willard Decker • Michael DeSalle • Fein • Finney • Karl Franz • Gaffney • David Garrovick • Hadley • Idelson • Ilia • James T. Kirk • Winston Kyle • Roger Lemli • Jabilo M'Benga • Leonard McCoy • Marla McGivers • Marlena Moreau • Number One • Carolyn Palamas • Elizabeth Palmer • Christopher Pike • Janice Rand • Kevin Riley • Saavik • Montgomery Scott • Elizabeth Sherwood • Solok • Spock • Stang • Hikaru Sulu • Nyota Uhura • Xon • unnamed ISS Enterprise personnel|