Territory, Vulcanis, Argus
Territory- The Yorktown is transporting Tellarite ambassador Gral to the Organian system to discuss territory concessions with the Klingon Empire. Without warning, the Yorktown is ruthlessly boarded by a group of supposedly "renegade" Klingons, with Gral being beheaded. April must use all his talents to convince the Klingons to let his ship free and to cede the Organian system to the Federation. He is helped immensely with this task by the Klingons' Organian "prisoner."
Vulcanis- The Yorktown is to be present at the momentous re-opening of the planet Vulcan. They are to transport a group of humans, including school teacher Amanda Grayson, to the planet, but are attacked on the way by a renegade sect of Andorians. Skon and his ship show up to help the Yorktown, and Skon's son Sarek is able to negotiate safe passage with the Andorians. They arrive on Vulcan at the grand re-opening ceremony.
Argus- The Yorktown arrives at the newly opened pleasure planet of Rigel IV, operated by the Rigelians of Rigel V. While attempting to enjoy their shore leave, the vacation colony is attacked by ships from the moon Argus. April must rally the vacationers to attack the shelled Argosians, who refer to themselves as "true Rigellians" and discover their connection to the planet.