"Please don't turn your back on me." 

A really strong episode. Perhaps the strongest of Gatwa's era thus far. A tense, atmospheric, well paced adventure, that feels pretty tightly packed in its scope. It's a science fiction horror, and that's what it does. The sets are brilliant at creating a sense of claustrophobia and unease, and the main villain is brilliant. A well thought out premise and powers, with interesting uses.

Rose Ayling-Ellis is the total stand out.