“We don't get aliens in Sheffield.” In a South Yorkshire city, Ryan Sinclair, Yasmin Khan and Graham O'Brien are about to have their lives changed forever, as a mysterious woman, unable to remember her own name, falls from the night sky. Can they believe a word she says? And can she help solve the strange events taking place across the city?

India, 1947. The Doctor and her friends arrive in the Punjab, as India is being torn apart. While Yaz attempts to discover her grandmother's hidden history, the Doctor discovers demons haunting the land. Who are they, and what do they want?

On the edge of a Norwegian fjord in the present day, the Doctor, Ryan, Graham and Yaz discover a boarded-up cottage and a girl named Hanne in need of their help. What has happened here? What monster lurks in the woods around the cottage - and beyond?

On the planet of Ranskoor Av Kolos, a battlefield, a conflict-scarred survivor, and a deadly reckoning await the Doctor, Ryan, Yaz and Graham.