The production values here are pretty good, and a lot of great cinematic choices have been borrowed from the great thriller/horror movies of the 70s. There is a really strong musical motif, lots of long shots and allowing of the camera to linger in places where the action isn't happening. The borrowing is well done and does the job of building a nice sense of suspense.
Beyond the style there's probably only just enough substance to push it up to a seven for me. Other reviewers are right - there's nothing new in the plot. It's your bog standard summoning-of-spirits-through-the-innocence-of-children trope set in a creepy as heck house with lots of windy sounds, unexplained banging and a subterranean extension that looks suspiciously free of rising damp for a manor house in Wales.
However the characters warm things up a bit with a script that doesn't try too hard and some sound acting, although Australian James Frecheville struggled a bit I thought with a role that required him to be dumber than a bag of hammers, and was, I think, intended to provide a small note of comic relief.
Six hours is a lot of screen time and a 'thriller' is hardly going to be thrilling for each of the 360-odd minutes. For my money though each of the episodes did just enough to warrant moving onto the next.
The ending isn't going to make everyone happy, although it attempts a lot harder than many other productions these days to provide some kind of resolution, although there are bunch of ends still loose when the credits role. Ultimately, like a like of thriller/horror, the ending is a lot less satisfying than the unravelling of the mystery to get there.
I thought it was a brave attempt to do some good old fashioned film making within the 'new' context of television, and no-one embarrassed themselves.
And I, for one, thought her fringe was awesome.
