As we enter the final days of the classic series we are presented with yet another overly complex story. It's convoluted plot almost doesn't matter though as it is ultimately a brilliant piece of television, despite being difficult to keep up with.

The 7th Doctor and Ace stay in the past in The Curse of Fenric, which is where they thrive. This time The Second World War, another perfectly Doctor Who-ish period in history. I love the central mystery - what tripped up both the Vikings and the Russians on the shores of this small village?

Whereas most stories they are given can barely live up to McCoy and Aldred’s simmering potential, here our leads are giving plenty to work with. Thrilling interactions with the priest, translating ruins, with the decoding expert, showing off their logic skills, with the decoding “girls”, local teenagers and “the old bag”. Once you throw the army officer and Russians in you’d think it would be overstuffed but it’s amazing how well paced everything is. Each character is given a substantial, natural feeling introduction that delivers them as fully formed people in the story. There is a real sense of place to this village. A much better use of budgets than alien worlds.

The sense of journey is the key that makes this story sing. You get a sense of how this moment in time fits into Ace's life as a whole, helped by call-backs to that haunted house from the last story - she feels like a real person, which is a step forward for the show. At the same time you get a sense of the importance Ace has in The Doctor's life whilst it is revealed how he has challenged and beaten Fenric before - many, many years in his past. This story makes the narrative of the wider show richer and more interesting follow and for that - it is one of McCoy's best.