Jake Willis was a human living in the 2020s. A former police officer and married to astronaut Adam Lang, he struggled with confidence issues and struggled to comprehend how a man as impressive as his husband could be interested in him. This caused tensions in their relationship when he failed to see Adam off on his way to the International Space Station.
Upon Adam's return to Earth and infection with the praxeus bacteria, Jake confronted his insecurities, located his husband and comforted him during his uncertain recovery. He later flew Suki's dangerously faulty ship and dispersed the praxeus antidote into the Earth's atmosphere, curing the disease and subsequently being rescued by the Doctor. He and Adam then rekindled their relationship and joined Gabriela Camara on her travels. (TV: Praxeus)