An exciting action-packed opener to Once And Future. This one involves the degenerated Fourth Doctor chasing the Monk through time and becoming embroiled in an alien invasion by creatures he defeated with Sarah Jane back in the 70s.

The Hyrinth are decent enough monsters, although I'm not sure they'll catch on in the same way as the Sontarans or the Ice Warriors.

The highlight is hearing the Tom Baker era and the new series collide. Hearing the Fourth Doctor meet Kate Stewart and Osgood offers something fresh and new.

We also get some lovely character moments between the Fourth Doctor and Sarah Jane. I do feel for Sarah with the Doctor refusing to take her back home. As the Doctor's best friend, that must have hurt.