The Defiant is transporting an Orb which the Cardassians are returning to Bajor - the Orb of Time. Also present is a human merchant who was trapped on Cardassia by the Klingon invasion. The merchant is actually Arne Darvin, a disgraced Klingon spy whose downfall came 105 years ago at the hands of James T. Kirk. Darvin uses the Orb to transport the Defiant back to that time period. The DS9 officers must infiltrate the Enterprise and space station K7 to stop Darvin from assassinating Kirk, and at the same time must prevent the timeline from being altered.
