A very interesting one. This instalment introduces us to Apex Foster, a time and space traveler who documents alien species. The claim that something is affecting the Doctor's timeline feels like a deliberate tie-in to the 60th. Apex proves a great Doctor substitute, and still feels different enough to be his own character.

The Torchwood sub plot seems as though it could go somewhere interesting, and I do wonder if any Torchwood personnel from TV could pop up. Gwen Cooper perhaps?