Season 5 is basically one novel spread over a number of shorter stories, we see a brand new threat to the cosmos that the Doctor battles on and off over the year.  Also features the weird and wonderful Gallifornication where the Doctor retires, but not for very long as events on Gallifrey need her attention.

In many ways this season was inspired by Buffy the Vampire Slayer, in that there is one major villian for the whole season as well as the return of old friends and enemies along the way.  It's not as long or as daring as the last season, but I didn't want it to be.  I wanted to return to more 'traditional' story telling while still keeping things fresh and interesting.