Episodes Broadcast: 2020-2022

London-born Jo Martin made her professional debut in 1988, in the Denzel Washington movie Queen & Country. Her first television part came in an episode of The Bill the following year. Martin had guest appearances on various programmes throughout the Nineties, including The Brittas Empire, Dodgem, The Real McCoy and Chef!. After the turn of the century, her first regular role was on the sitcom The Crouches. Martin's other television credits that decade included Always And Everyone, Doctors and Casualty, while Batman Begins numbered amongst her occasional films. Her career maintained its steady pace during the 2010s, when she could be seen in shows like Top Boy, Jonathan Creek, Fleabag and Back To Life, plus movies such as 4.3.2.1., Devil's Playground, Chalet Girl and 100 Streets. Martin gained a new prominence at the end of the decade, when she had a regular role in three seasons of Holby City.

Then, in 2020, Martin took a role in the Doctor Who episode Fugitive Of The Judoon. It appeared that she was playing a tour guide named Ruth who became unwittingly ensnared in her husband's mysterious dealings. However, viewers were as shocked as Jodie Whittaker's Thirteenth Doctor when Martin's true role was revealed to be the so-called “Fugitive Doctor”, a forgotten incarnation who predated the start of the television series itself. Martin made three further appearances as the Fugitive Doctor, latterly in Whittaker's final adventure, 2022's The Power Of The Doctor. Her other credits around the same time included The Flatshare, Death In Paradise and Midsomer Murders.