The Doctor turned to Grace and said: "I don't suppose you have a plan for getting out of this one?"
When the Doctor and Grace arrive on the "charming" planet Paracastria, they quickly find that it is anything but. Armed thugs attempt to kidnap a native woman from the streets; a journalist named Sophie breaks into the Institute of Science. A boy called Wil busks on the streets, hiding from his family.
Doctor Grace Holloway is admitted to the local hospital, suffering from burns and smoke inhallations. She claims to have been involved in the fire that destroyed the Institute of Science. But the Institute is still standing, and Grace is still by the Doctor's side.
Perhaps these events are related. But as a religious cult completes it's plan for planetary dominance, it is once again up to the Doctor to save the world.