Doctor Who: The Tribulations of Thadeus Nook

This story sees the Doctor and Leela pursuing an irresponsible time traveller whose actions are inadvertently changing history. The first part focuses on the chase, with an introductory action piece and then a whistle-stop tour across time and space. The Doctor and Leela are, as so often, separated for much of this section, and it's Leela who ends up with the better scenes. That's mainly because she gets to interact with the antagonist and his girlfriend who are considerably more interesting than the non-entity the Doctor ends up being paired with.

Things take a turn at the halfway point, as we encounter the real villain and the fight is on to save the course of history. Although the plot is more focussed here, I found it less entertaining, possibly because the history in question is that of the future, and had little relevance to us in the real world. Plus, neither the villain nor his main sidekick are particularly well-developed, with the former just being shouty and gravelly-voiced. (He might, of course, come across better in a visual format with decent prosthetics or CGI, but here, we're just left with the vocal effects).

But there is plenty in this story about time travel itself, and without it being especially timey-wimey. That is, there's quite a lot about how you could use time travel to break things, but there are no paradoxes and the part that's out of (external) chronological sequence is fairly straightforward as such things go. There's a good use of a small cast to imply a larger range of characters, even if those does lead to some dodgy accents in places. Taken together, that's enough to raise this above average, even if the villain isn't.