In 2268, the Enterprise, then under Kirk's command, was assigned to deliver a revolutionary medicine to Cory which would cure the colony's inmates of their mental illnesses. However, by the time the Enterprise arrived, the colony had been taken over by the inmates, led by Fleet Captain Garth, and Cory was imprisoned.
When Kirk and Spockbeamed down to the planet, they were greeted by Garth, who impersonated Cory again. The truth was soon revealed, however, and Garth revealed his true form.
When Kirk refused to give Garth information needed for the latter to board the Enterprise and take command of the ship in Kirk's place, Garth placed Cory in a rehabilitation chair which had been "refined" to be used as a torture device. He used the device on Cory, causing the governor severe pain, but Kirk still refused to disclose the information.
Garth was eventually overthrown, and Cory oversaw the Fleet Captain's rehabilitation treatment, which was a success. (TOS: "Whom Gods Destroy")