Cameras follow Russell T Davies as he returns to Doctor Who. The writer also talks to Alan Yentob about his career, from his beginnings in children's TV to 2021's critically acclaimed drama about the Aids crisis, It's A Sin. Featuring interviews with David Tennant, Catherine Tate, Ncuti Gatwa, Helena Bonham Carter, Olly Alexander, Sally Wainwright and Caitlin Moran