On the planet Lobos, the Doctor stops a brutal war between the indigenous Lobos and human settlers. It is only after the TARDIS leaves that Ryan realizes that he left his phone on the planet. Again. Upon his return, the Doctor discovers that the TARDIS has zipped hundreds of years into the future - and something has gone horribly wrong. The cult of the "Great Doctor", proclaimed by people, turned the Lobosians into their slaves. It was time for the Doctor to prepare for the consequences of his visit. Will she be able to fix everything if the Lobos are already on the verge of death?Meet the Thirteenth Doctor, Yasmin, Ryan and Graham, played by Jodie Whittaker, Mandeep Gill, Tosin Cole and Bradley Walsh.