Templeton was Sir Toby Kinsella's assistant in 1965, hired in large part because he knew 'the right people'. He was diligent but smarmy, with a patronisingly misogynistic streak. Sir Toby told Catherine Waverly that Templeton was “from the old school, even older than mine." (AUDIO: Manhunt) Nobody at the Intrusion Countermeasures Group was sure if "Templeton" was his first or surname. (AUDIO: Sins of the Father)

For the first few weeks of his job, he mainly sat as a proxy for Sir Toby on committee meetings (AUDIO: Sins of the Father) but also carried out underhanded tasks he didn't want Countermeasures to know about. (AUDIO: The Fifth Citadel)

He showed a callous streak when Countermeasures went to him about the Wilcock Institute mutants: he had soldiers open fire on sight without regard for civilians and at the Institute itself, had it flooded with nerve gas when Sir Toby and Countermeasures were still on site. Soldiers objecting to the latter were threatened with being shot. While Sir Toby was under inquiry for the affair, (AUDIO: Sins of the Fathers) Templeton was left in charge and began to anger the team by demanding all decisions went through him and forbidding any independent action. He intended to keep the job by suggesting the parliamentary inquiry was done by new, up-and-coming politicians — William Heaton MP knew Templeton was doing this in the hope it would doom Kinsella but he considered Templeton to be incapable of handling the Group.

To make a point, Templeton went "missing" when Countermeasures needed approval to rescue Allison Williams. They went ahead anyway and Sir Toby was cleared by the inquiry. Templeton was booted out and then stopped from stealing files. (AUDIO: Changing of the Guard)

A while later, when Allison was suffering from memory loss, he took her for private medical treatment — while Countermeasures were out of the country. Her memory was restored but she was also brainwashed, revealing Templeton as a member of Klaus Werner's Project Othello. Templeton reclaimed Sir Toby's job and altered Allison's mind so she thought he was Kinsella. (AUDIO: Unto the Breach)

He later got Rachel to believe he was Kinsella as well. After an explosion he put all the team on leave.(AUDIO: New Horizons) He tested Jenson when her condition fell. Jeffrey Broderick mentioned that Templeton was funding his research. (AUDIO: The Keep) He was a Light Sleeper and was planning the destruction of the Human race due to the Light's disappearance. He took Kinsella hostage and went to a set of the satellite launches. He was shot and killed. (AUDIO: Rise and Shine)