A Starfleet commodore with no command experience who took over the Enterprise when Kirk aged rapidly, and led it into danger.
Stocker is a commodore travelling aboard the Enterprise to take command of Starbase 10 when Kirk and much of the landing party begin aging rapidly after exposure to radiation on Gamma Hydra IV. Stocker arranges a competency hearing that removes Kirk from command and then assumes it himself.
A desk officer with no experience of the captain's chair, Stocker takes a shortcut through the Romulan Neutral Zone and the ship is soon surrounded by Romulan vessels. After McCoy finds a cure, Kirk resumes command and bluffs the ship to safety. Stocker was played by Charles Drake.