Star Trek: The Original Series - 125 - Garth of Izar

GARTH OF IZAR: The legend of Captain Garth, the hero of Axanar, has spread throughout the Federation. His exploits are required reading at Starfleet Academy -- where he became a hero of a future legend, James T. Kirk...

GARTH OF IZAR: Brutal injuries sustained on Antos IV forced the native Antosians to heal him by means of giving him their natural shape-changing abilities. But the cure proved worse than the disease, as Garth was driven insane...

GARTH OF IZAR: His madness apparently cured at the rehab colony on Elba II, Captain Garth has returned to service to mediate a crisis on Antos IV, with the aid of Captain Kirk and the Starship Enterprise™. But has Garth truly put his insanity behind him, or will he renew his plans for conquest -- starting with the Antosians?

Pamela Sargent and George Zebrowski are both Nebula Award winners and have won many other awards for their work.