After the events of Star Trek VI: The Undiscovered Country, Spock returns to Vulcan while Captain Kirk must face the Klingon Empire as never before.

When Spock finds out his mother is dying, he returns to Vulcan to be with his parents. But when his father, Sarek, is called away on duty, both father and son must work together to foil a far-reaching plot to destroy the Federation.

At the same time, Captain Kirk and the crew of the USS Enterprise are forced to penetrate the heart of the Klingon Empire, where Kirk’s last living relative has become a pawn in a deadly battle. With Sarek’s help, Kirk and his crew quickly learn that all is not as it seems. Before they can protect the Federation, they must see the face of their hidden enemy…an enemy more insidious and more dangerous than any they have faced before.