"Star Empire" is the Federation's most powerful new weapon—a dreadnought, first in a class of super-starships—capable of outgunning a dozen Klingon cruisers, or subduing a galaxy. On the eve of her maiden voyage, "Star Empire" is stolen by terrorists who demand a rendezvous with the Starship Enterprise™—and with Lieutenant Piper, stationed aboard Kirk's ship on her first training cruise. Now Piper must discover why her friends from Starfleet are among the terrorists... and why they insist the ship was stolen not to attack the Federation—but to save it!

Back on Earth enjoying a well-deserved shore leave, Captain Kirk is rudely accosted by a trio of Starfleet Security guards. It seems he is wanted for questioning in connection with the theft of transwarp—the Federation's newest, most advanced propulsion system. Could Captain Kirk, Starfleet's most decorated hero, be guilty of stealing top-secret technology? With the aid of Mr. Spock, Lt. Cmdr. Piper begins a desperate search for the scientists who developed transwarp—a search that leads her to an isolated planet, where she discovers the real—and very dangerous—traitor!