Captain Mike Yates is a core member of the UNIT "family", always looking out for the Doctor and his companion and dedicated to carrying out the Brigadier's orders to the best of his ability. Yates is an impulsive person, rushing to wherever he feels he needs to be in order to capture a bad guy or rescue a good one. Although he may find himself in a sticky situation from time to time, Yates is very quick-thinking and fast-talking. He is also a remarkably good actor, able to deceive people into believing that he is someone he's not.
Aside from the usual army training, which has made Yates an excellent fighter and marksman, he is able to ride motorcycles. Yates has a very sarcastic sense of humor, often firing quips at his fellow officers, the Doctor and the Brigadier (who is not always amused). He also enjoys pulling rank on his fellow officers when it has advantages - such as a bit of confiscated food!
Yates' time with UNIT comes to a close when he falls under the spell of Operation Golden Age, an organization dedicated to bringing about world peace by turning back time to a simpler age, and allowing their devotees to guide the citizens of the Earth's past to a more enlightened future, without war or pollution. Believing in their ideals, which they claim to be obtaining through nonviolent means, Yates agrees to sabotage the Doctor's equipment, and even goes so far as to pull a gun on his superior officers. He is given the chance to take extended sick leave and retire quietly, and he takes advantage of the opportunity to relocate to a monastery and find peace. Having done this, he temporarily joins forces with UNIT again to help the Doctor defeat the giant spiders of Metebelis 3.
