Kirk is contacted by Leighton, a friend from Kirk's stay on the Tarsus IV colony years ago, who believes that Kodos the Executioner, the militant dictator who gave the order for scores of people to die on the colony during Kirk's stay, is at large once more in the guise of touring Shakespearean actor Karidian, who, with his touring company, has stopped over at Leighton's post for a performance. Kirk isn't convinced until Leighton turns up dead, leaving Kirk and Lt. Riley the only remaining living witnesses of the Tarsus IV massacre. To investigate further, Kirk invites Karidian's company to travel on the Enterprise to their next performance, and attempts on Kirk and Riley's lives begin immediately.
