When the newly-christened starship Enterprise's shakedown cruise goes poorly, Captain Kirk and crew put her into Spacedock for repairs. But an urgent mission interrupts their Earth-bound shore leave. A renegade Vulcan named Sybok has taken three ambassadors hostage on Nimbus III, the Planet of Galactic Peace. This event also attracts the attention of a Klingon captain who wants to make a name for himself and sets out to pursue the Enterprise. Sybok's ragtag army captures the Enterprise and takes her on a journey to the center of the galaxy in search of the Supreme Being.