Plot hole: In the Pudding Club episode, when they visit the secret room, all the candles are lit even though no-one is in there.

Continuity: When Helen Grace is in the retired GP's house choosing which apple she will eventually stuff in to her victim's mouth, her hand wavers over one apple, but instead chooses another. At the end when we see a flashback of that scene, she picks up the first apple she was originally going for.