Yates' guard

Yates' guard worked at the Global Chemicals, where he was ordered by Jocelyn Stevens to keep Mike Yates under observation.

He was tricked into allowing Yates to speak briefly with the Third Doctor (disguised as a cleaner) when Yates said he left his briefcase in his office and went to get it. He and Stevens eventually found Yates in his office. When they left, the guard asked the cleaner how her husband was, not knowing it was the Doctor. (TV: The Green Death)