Giles Kent was the leader of a plot to take down Ramón Salamander. He had formerly been Deputy Security Leader for North Africa and Europe in the World Zone Authority, but had been discredited and ruined by Salamander when he got too close to exposing him as a madman; Kent found himself framed for corruption. A number of Authority figures he spoke to wound up dead, however.
In 2018, he had a base near to Salamander's Australian facility (TV: The Enemy of the World) in Cape Melville, (PROSE: Doctor Who and the Enemy of the World) with Astrid Ferrier as his second-in-command. When he saw the Second Doctor's resemblance to Salamander, he persuaded the Doctor to impersonate Salamander and assassinate him. Kent not only pushed the Doctor into this, but he also forced him into his first impersonation by tipping off an alleged agent of Salamander.
Kent had actually been Salamander's ally five years prior and was the one who brought Salamander's scientists to the underground complex, and had simply fallen out of favour with the demagogue. He secretly planned to take over Salamander's operations. The Doctor, however, had always suspected him because of his ease with murder.
After the Doctor exposed him, he retreated into the tunnels. It was here that he encountered Salamander, who betrayed Kent by shooting and wounding him. Staggering into the explosives area, Salamander pursued him and was about to finish him off, when Kent pulled the main lever, triggering the explosives. (TV: The Enemy of the World)