Well, that was pretty intense! US fans saw it last Friday, but the hotly anticipated return of Battlestar Galactica hit UK screens this evening, and just in case you clicked onto this page by mistake, we've hidden our comments on episode 4.13 ("Sometimes A Great Notion") below - highlight the text to read it.

HIGHLIGHT HERE IF YOU WANT TO KNOW:

"FRAK EARTH!" reads the graffiti in one of the Galactica's corridors. This is the exciting return that we were waiting for; sci-fi doesn't get much more thrilling - or morose - than this. The title of the episode is almost certainly taken from an old folk song called “Goodnight, Irene”: "Sometimes I get a great notion/To jump in the river and drown" and you can see how this applies to the theme of the episode.

The Cylons and humans working together have found the Earth, but it was nuked about 2000 years ago. And the remains they find seem to confirm that the lost 13th tribe were Cylons, not humans. Yikes. The gritty, washed out opening scenes couldn't really have been bleaker and you can tell from just five minutes in, as Dualla weeps over a child's plaything, that it's not going to have a cheerful resolution. We're wrongfooted because she seems to have reconciled herself to the situation and is even giggling with Lee after a drink at the bar. So when it comes, Dualla's suicide is sudden, effortless and heartbreaking.

And what do discoveries on the surface mean for Starbuck? If she's not the final Cylon (and the revelation that it was Ellen Tigh all along is unexpected but dramatically played in the final moments) then how do we explain her dead body in the crashed Viper?

The pacing is noteworthy. There's a great deal of silence, and hardly any dialogue at first - even Roslin's returning address to the fleet is just her shaking her head. The only mis-step is Bill Adama's over-long drunken session with Saul Tigh, which seems to drag although it is excellently acted. The episode delivers a few answers, tugs on plot threads we've been following for years, and asks enough new questions to mean we can't wait for the rest of the season. It has a mythic sense about it, branching out from the usual on-ship claustrophobia to place our favourite characters in the context of a wider, ancient, confusing universe - there's a sense of madness about it too (insanity borne of disappointment, no doubt).

And so the journey beings again, to find a new home that isn't Earth! One thing's for sure - this is not a TV show to watch if you've had a bad day...

So, what did you think of the show? Is the final Cylon somebody you'd guessed? We bet it wasn't (unless you caved and read all the spoilers from the US on the net already).

Share your thoughts below in the comments thread, or head to the forum. Where do you think the season's going to go now? We linked to some of the speculations about what this all means, back here. You can read our "official" Spoiler Zone reviews of Battlestar Galactica, complete with star ratings, in the pages of SFX magazine.