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?

• BBC
• Jodie Whittaker
• Bradley Walsh
• Mandip Gill
• Tosin Cole
• Sharon D. Clarke
• Samuel Oatley
• Jonny Dixon
• Amit Shah