In the Dark Mirror continuity, Sarek was an ambassador. Spock had transferred off the I.S.S. Enterprise shortly after a transporter accident had brought visitors from the primary universe, and supported a program of reforms until his former Captain James T. Kirk, now the Emperor of the Terran Empire, framed him for treason and had him executed in 2279. Shortly after Spock's execution, Sarek himself was assassinated by another Vulcan seeking Sarek's position.