Gat was a Time Lord who worked with the "Fugitive" Doctor (TV: Fugitive of the Judoon) for the Division. (TV: The Timeless Children) She worked with the Judoon to capture the Doctor following their disappearance, and upon discovering the Doctor's location, she executed Lee Clayton and proceeded to search for the Doctor. When she captured the Doctor, Gat was surprised when she was confronted with another incarnation of the Doctor, the Thirteenth Doctor. She cited the Blinovitch Limitation Effect, terming it an "abomination." When she later revealed to the other Doctor that she was an agent of Gallifrey, Gat was horrified when the Thirteenth Doctor told her Gallifrey was gone in her time, destroyed by the Spy Master, and presumed she was lying.
Gat was killed when she tried to shoot the Fugitive Doctor with a laser rifle, as the Doctor had re-calibrated the weapon to shoot the one holding it. (TV: Fugitive of the Judoon)