Long ago, before the days of myth and legend, our worlds belonged to them. Now they want them back. . . .

Captain Kirk is stunned when the Federation receives an urgent plea for help -- from the Klingon Empire. A mysterious starship has invaded Klingon space and resisted all their efforts to destroy it. Establishing contact with the stranger's ship, Kirk discovers that it is only the vanguard of a vast alien fleet obsessed with conquering the Klingons, the Federation, the Romulans, and all who dwell in the space that was once their own.

The Invasion has begun. . . .