A tale of two halves, with the first offering up an incredible premise, curveballs and payoff, but then the second fails to deliver on any promise from earlier in the story, becoming perfunctory.

The Bio growers is a chilling and well realised concept. And every Doctor needs to have a body swap story at some point, right?

A very powerful and gripping story, which deals with a morally grey premise (that of placing people's minds in bodies that are in a vegetable state. The Biogrowers really are a chilling concept, and the Doctor and Amy body-swapping stuff is absolutely brilliant (I wish we'd got to see that on-screen, especially the hilarious moment Rory accidentally kisses the Doctor thinking it is still Amy in his body). I would absolutely recommend this story to anyone craving more 11.