Ross Brimmicombe-Wood

Colonel Ross Brimmicombe-Wood was a Scottish career soldier and commanding officer of both UNIT and ICIS.

Early life
Colonel Brimmicombe-Wood's father, Archie, was also an army officer and had been friends with Charles Crichton and Robert Dalton's father. (PROSE: Project: Valhalla) He was a friend of Colonel Emily Chaudhry and would often call her an "English rose" before she drunk him under the table. (AUDIO: The Longest Night)

The rise of ICIS
Years later, as a colonel, he was the commanding officer of the UK branch of UNIT, Brigadier Bambera having left sometime after 2001. (AUDIO: Animal) He was believed to have been abducted while escorting an alien spacecraft across the country in 2005. (AUDIO: Time Heals)

In reality, he was the commanding officer and a double agent for ICIS. He had faked his own kidnapping to create chaos in UNIT. He was involved in attempts to bring down the British government for reasons of ultra-nationalism, and was imprisoned for his actions. (AUDIO: The Wasting)

Behind the scenes
The character had originally appeared in Sympathy for the Devil, an alternate universe story from the Doctor Who Unbound series. That version of the character had been a loyal soldier, allowing the UNIT audio series to play off the fact the audience already knew him and wouldn't expect him to be an antagonist.