Captain Kirk aboards the new enterprise during it's maiden voyage, for a publicity event. However, what was supposed to be a routine maiden voyage to test the new ship's capabilities soon turns into a serious mission; which requires Kirk's services one last time.

Long story short, Kirk saves the ship, but he's caught by a temporal nexus, and he's assumed to be dead ever since. Fast forward to seventy eight years later, and we're at the next generation of the enterprise.