Orbiting a quiet backwater planet, the massed forces of the universe's deadliest species gather, drawn to a mysterious message that echoes out to the stars. And amongst them, the Doctor. Rescuing Clara from a family Christmas dinner, the Time Lord and his best friend must learn what this enigmatic signal means for his own fate and that of the universe.
The Rani is a fictional character in the British BBC science fiction television series Doctor Who, portrayed by Kate O'Mara, Anita Dobson and Archie Panjabi. She is a renegade Time Lord, and a nemesis of the series' title character, a Time Lord known as the Doctor. The Rani is an amoral biochemist who experiments on humans and other species, and considers everything secondary to her research.