Sergeant Tom Osgood was a UNIT technical officer who served under Brigadier Lethbridge-Stewart.

Osgood joined UNIT shortly before the Third Doctor's arrival, as a corporal. He was the most technically proficient UNIT soldier, having attended universities, where he studied scientific subjects, although he admitted that he was out of his depth where the Doctor and Liz Shaw were concerned. (PROSE: The Eye of the Giant)

After he was promoted to sergeant, (PROSE: The Scales of Injustice) he was called in to assist in the rescue of the Doctor, Jo Grant, Sergeant Benton and Captain Yates from the heat barrier that surrounded Devil's End. With the Doctor's help, he devised a way to penetrate the heat barrier. (TV: The Dæmons)

Soon after this, Osgood became engaged to a woman named Becky, whom he met at a folk festival. (PROSE: Dancing the Code)

Osgood retired from UNIT shortly after the Devil's End incident. (AUDIO: The Scream of Ghosts) By 1983, Osgood and Yates had set up tiny tea-rooms just outside Reading. (PROSE: Business Unusual)

In 2001, Osgood was a civilian in his fifties. He was brought in to help UNIT and the Sixth Doctor with an alien incursion. (PROSE: The Shadow in the Glass)

Osgood was invited by the Eighth Doctor to have Christmas dinner at the Brigadier's house. (PROSE: Faithful Friends: Part 3)

Behind the scenes Edit