Spock, and Dr. McCoy struggle to establish new lives apart from each other and the starship. The newly-promoted Admiral Kirk is placed in charge of a specially-created Starfleet division and attempts to defuse a critical hostage situation; Mr. Spock, who, in the midst of a teaching assignment on Vulcan, finds the one thing he least expected; and Dr. McCoy, whose unerring instinct for trouble lands him smack in the middle of an incident that could trigger an interstellar bloodbath.