“Worlds lived, worlds died. Nothing will ever be the same.” The crossover starts on Supergirl S05E09 Crisis on Infinite Earths: Part One (I), Batwoman S01E09 Crisis on Infinite Earths: Part…

Separated from The Doctor, Clara discovers a new menace from another dimension. But how do you hide when even the walls are no protection.

The Doctor and Clara, with their old friend Rigsy, find themselves in a magical alien world, hidden on a street in the heart of London.