The Doctor and Clara, with their friend Rigsy, find themselves in an alien world, hidden on a street in the heart of London. On that street are some of the most frightening beings imaginable, and Ashildr!

There is death in the air, and not all the visitors will get out alive.

The Doctor and Clara, with their friend Rigsy, find themselves in an alien world, hidden on a street in the heart of London. On that street are some of the most frightening beings imaginable, and Ashildr!

There is death in the air, and not all the visitors will get out alive.