After Tuvok crash lands on a moon that is considered sacred, he attempts to save three abandoned children,  while also repairing his shuttle.

Stardate: 49655.2 While returning from an away mission, a transporter accident merges Tuvok and Neelix into one new being with the personality of both combined. He calls himself "Tuvix." But the  Doctor's search for how to restore their original forms causes a moral dilemma as Tuvix does not wish to be terminated.