Ianto Jones was a junior researcher at Torchwood One who later joined Torchwood Three. He first approached Captain Jack Harkness with enthusiasm about joining Torchwood Three in Cardiff, eventually winning him over. He initially served as more of a "support man" or "tea boy", but later took a more active role in missions

John "Soap" MacTavish is a member of the British Special Air Service (SAS), a member of Captain Price's Bravo Team, and the main protagonist in the Modern Warfare storyline

Leonard H. McCoy, MD was a noted physician and scientist of the 23rd and 24th centuries. McCoy was an accomplished surgeon, physician, psychologist, and exobiologist, and was also considered an expert in space psychology. As ship's surgeon and chief medical officer, he served aboard the USS Enterprise and USS Enterprise-A for a combined twenty-seven years.