Doctor Who: Every Doctor's DEFINITIVE Episode

9. The Curse Of Fenric (The Seventh Doctor)

The Curse of Fenric is a hugely atmospheric story that takes in World War 2, biological weapons, impossible chess problems, and evil from the dawn of time. It's also the culmination of various threads that had been left dangling by script editor Andrew Cartmel and his writers from Dragonfire onward.

Overseeing it all is Sylvester McCoy's Seventh Doctor, who is at his most mercurial, striking the perfect balance between clown and chess master. He entertains a baby with birdsong while plotting a final showdown with an ancient evil, and it all flows naturally. This is a Doctor that came more into his own as his era progressed, and he was at his peak here.

And then, at the very heart of it, is the Doctor and Ace's relationship being put to the ultimate test. It's heartbreaking to watch, all the more because of Sylvester McCoy and Sophie Aldred's very real friendship. This is the story where the dark truth of the Doctor's manipulations was revealed so it was a huge, definitive point for their relationship and era as a whole.

Both performers put in their finest performances in a multi-layered script, making The Curse of Fenric the gold standard of Seventh Doctor stories.