When Demora Sulu, an exemplary young Starfleet officer, suddenly attacks her commanding officer, who kills her in self-defense, everyone is stunned. No one is more grief-stricken than her father, Captain Hikaru Sulu of the U.S.S. Excelsior. Determined to learn the truth behind his daughter's bizarre death, Sulu goes to the planet where she was killed, and finds himself confronted by an old enemy eager to destroy Sulu's reputation and his life!