Darn those high-gravity black stars! Always accidentally throwing starships hither and yon through time. Although in this case, the crew of the Enterprise manages to correct all the problems they caused by beaming 1960s Air Force pilot Captain John Christopher on board.

As the new captain of the Enterprise and other new members of his crew become acquainted with their galaxy class starship and its capabilities, they travel to a curious city on Deneb IV and also encounter a powerful being from the Q who, among other things, exhibits a possible power over time itself.