Castrovalva

The problem with linking stories, as JNT would later discover, is that after the event, they are very rarely treated as being linked. Even "Trial", united by on-screen umbrella title and linking scenes, is still dissected into constituent parts by us fans, leading to nonsensical remarks like "Mindwarp is a bit crap". So is "The Space Museum" Episode 3, but what are you going to do about it? This is a different battle, however. Don't get me started.

"Castrovalva" is even more doomed to be lessened in appeal by its status as part of a series of stories, stretching back to "The Keeper of Traken" and half-finishing at the end of it's Part 4 with that winning Peter Davison smile. I say "half-finishing" because one could carry the definition forward through Season 19, a succession of tales bookended by nods like references to the Mara and Nyssa fainting so Sarah Sutton could go shopping - but it's possible to go too far. At the very least, "Castrovalva" deserves to be considered sandwiched within a trilogy, taking the events of "Logopolis" (whose cliff-hanger it even reprises) into account when judging it.

But naturally you don't think of "Castrovalva" as the second half of an eight (or even a twelve) part adventure; your memory and view of it begins mid-adventure in a field, and progresses through two episodes of character-building TARDIS scenes. It's often remarked that the story "doesn't get going" until Episode 3, which kind of proves the point. Left with the fallout from "Logopolis" to clear up, "Castrovalva" is less a story in its own right than half an apology for everything there isn't time to do in the last moments of the Tom Baker era; getting to know Tegan and Nyssa, exploring how the new TARDIS crew are going to fit into the show (they're even designated roles in Part 1, though they aren't very helpful ones) and washing away the last fractured remains of the old regime.

It's a shame things had to be this way, because there is a beautiful story within "Castrovalva" as well - albeit one as substantial as the creations the Master has created using the Power Lines. Yet the non-believability of "Castrovalva" is what makes it so special. The confusion over the four town squares, the Doctors mulling over a history older than the paper it's written on, and a realisation by the Castrovalvans that they don't even exist are all magic moments. It doesn't, perhaps, capitalise on the "what if I'm a figment of somebody's imagination?" dilemma as effectively as it might, but the idea's are there.

Like Castrovalva itself however, the majesty of the destination is clobbered by the journey there. None of the three leads are strong enough at this point to carry the early episodes alone, although perhaps that's not the point of the enterprise. Imagine the TARDIS crew of two seasons on making this trip, and you begin to see the merits in using it to get to know these young characters. There are no grudges, no hang-ups and none of them want to kill the Doctor. It's like they've all just started University, flung together in unreliable accommodation trying to help someone they don't know stay conscious. "Castrovalva", surely, was an exploratory stepping stone, never designed to stand entirely alone, merely to bridge the era's it straddles.