Early in his five-year mission commanding the U. S. S. Enterprise, Captain James T. Kirk found himself caught up in a growing conflict on the planet Neural. To maintain the balance of power against a force being armed by the Klingons, he provided weapons to his new friends, the Hill People. Years later, Admiral Kirk learns that the Klingon presence on Neural has grown considerably, and in possible violation of the Treaty of Organia. Did his impulse as a young captain turn out disastrously wrong? Could he have done more to eliminate the Klingon threat? To find out, Kirk must embark on a secret mission back to Neural-- where he might just be the only person who can prevent an interstellar war.