Spock/Starfleet/James T. Kirk/Year One

After Pike's promotion to fleet captain, Kirk assumed command of the Enterprise in 2265, with Spock as his first officer. An early mission proved disastrous when Lieutenant Commander Gary Mitchell, a close friend of the new captain, developed enhanced psionic abilities when the Enterprise encountered an energy barrier at the edge of the Milky Way Galaxy.
Spock examined the tapes of an earlier ship, the , that had encountered the same barrier and was destroyed. As Mitchell's powers increased, Spock believed he had become extremely dangerous and feared that he would destroy the Enterprise. He therefore advised Kirk to either strand Mitchell on the uninhabited and desolate Delta Vega to isolate him from galactic civilization or kill Mitchell before it was too late. Kirk hesitated but initially attempted the former, but the scope of Spock's concerns were eventually borne out and Kirk was forced to kill Mitchell. ()