Hot on the heels of the acclaimed third series, Doctor Who returns for a fourth instalment with a familiar face alongside the Doctor.
8. Silence in the Library Sees the Doctor and Donna enter a world of terror inside an abandoned library. They're given only one warning: 'Count the shadows'.
9. Forest of the Dead The Doctor forges an alliance with the mysterious River Song. But can anyone stop the shadowy Vashta Nerada?
10. Midnight The whole shebang is wrapped up with "Midnight", where the Doctor is trapped, powerless and terrified on the planet Midnight, as the knocking on the wall begins...