Mike Yates

Captain Mike Yates is a fictional character in the British science fiction television series "Doctor Who", played by Richard Franklin. He was adjutant of the British contingent of UNIT, an international organisation that defends the Earth from alien threats.
Character history.
Yates first appeared in the Third Doctor serial "Terror of the Autons", the latest in a line of Captains assisting Brigadier Lethbridge-Stewart, although the Doctor implies that he was around for previous stories. He proved more durable than his predecessors, appearing semi-regularly in the programme from 1971 to 1974 alongside the Brigadier and Sergeant Benton. Together with the Doctor and his companions, Yates fought off alien invasions, the machinations of the renegade Time Lord known as the Master, rogue computers and mutated maggots.
Little is known of him outside of his time with UNIT. He was cool under fire, efficient, and both gave and carried out his orders with a minimum of fuss. He appeared to have a relatively good rapport with his men, although he did remind Benton on occasion that "rank hath its privileges". The Third Doctor's assistant, Jo Grant, was dressed up to go on a date with Mike at the start of "The Curse of Peladon", only to be taken on a trip in the TARDIS by the Doctor.
Yates's fall from grace started when he was brainwashed by the artificial intelligence BOSS in the 1973 serial "The Green Death". The brush with ecological disaster apparently made Yates very concerned about the future of the planet, and he was easily recruited by Sir Charles Grover into a conspiracy to reverse time and return Earth to a "golden age" ("Invasion of the Dinosaurs"). The conspiracy was thwarted by the Doctor, and in return for his past service to UNIT, the Brigadier allowed Yates to take medical leave and then quietly resign (actor Richard Franklin believes the initial plan for this story was to kill off Yates).
Trying to recover, Yates attended a meditation centre but uncovered strange goings-on, which he reported to Sarah Jane Smith, since he felt that UNIT would find him untrustworthy. Sarah communicated this back to the Doctor, leading into the rest of the events of the Third Doctor's last serial, "Planet of the Spiders".
Richard Franklin returned as an illusory image of Yates in the 20th Anniversary special "The Five Doctors" and reprised the role of Yates in the 1993 charity special "Dimensions in Time".
As one of the more prominent recurring supporting characters in the television series, Yates is often listed as a companion of the Doctor and indeed is listed as such on the official BBC "Doctor Who" website. However, he is not always listed as such - John Nathan-Turner's book "Doctor Who: The Companions," for instance, excludes Yates.
Other appearances.
Mike Yates has appeared in the spin-off novels taking place during his time with UNIT. In the Virgin Missing Adventures novels "The Eye of the Giant" by Christopher Bulis and "The Scales of Injustice" by Gary Russell, Yates began as a sergeant in UNIT together with Benton and was promoted to Captain at the end of "Scales", which took place between the television stories "Inferno" and "Terror of the Autons". The novel implies that he was promoted directly from Sergeant to Captain, which would be unusual if not impossible in most real-world militaries.
In the Past Doctor Adventures novel "The Devil Goblins from Neptune" by Keith Topping and Martin Day it was established that his full name was Michael Alexander Raymond Yates.
In the Past Doctor Adventures novel "Verdigris" by Paul Magrs, Yates is rendered amnesiac and subsequently turned two-dimensional. The Third Doctor later arranges for Yates to be restored to normal.
In Past Doctor Adventures novel "Deep Blue", we discover that Mike had three brothers, and his mum thought that Mike was the most sensitive.
Stories written as in-universe articles in "Doctor Who Magazine Winter Special" 1991, (subtitled "UNIT Exposed") described significant post-UNIT activity for Yates. He had founded an organisation called the Cosmic Earth Society, written a book called "Help From the Stars" which detailed the revelations of past extraterrestrial involvement in human evolution discovered by UNIT at Devil's End, and revealed other UNIT-operations information to a reporter from the "Metropolitan". His claim that the actual cause of central London's evacuation was dinosaurs having been brought forward in time (part of a plan that he admitted to have been involved in and which was, he claimed, the real reason for his discharge from UNIT) dovetailed with "Day of the Dinosaurs", an entry in a series of science fiction novels written by former UNIT associate Sarah Jane Smith, which featured an organization called WIN (World Investigative Network) commanded by General Lutwidge-Douglas. This lead another "Metropolitan" reporter to doubt that Yates was a crackpot as generally believed.
Richard Franklin also wrote an unpublished novel featuring Mike Yates, "The Killing Stone", set after the events of "Spiders". It was released as an audio book, read by Franklin, by BBV in 2002.
In 2009, Franklin reprised the role of Mike Yates for a series of five audio dramas produced by BBC Audio under the umbrella title "Hornets' Nest". The series saw Yates partnered with the Fourth Doctor, played by Tom Baker. He reunited with the Fourth Doctor in the subsequent sequel series, "Demon Quest" and Serpent Crest.