Time was that a Kate-centric episode of Lost meant a chance to sit back and have a nice snooze for at least 50% of the episode. The major questions about Kate's part were never that interesting, and worst of all, it usually meant an opportunity to deal with her on-again-off-again-tedious-again "relationship" with Jack - so it's a welcome change to find a Kate episode that doesn't spend too much time on these elements, and instead focuses on her.

That said, Kate's role in the episode is mainly a facilitator. The facilitator of Claire's journey to hospital. The facilitator of Sawyer's chance to grieve. And the facilitator of Jin's chance to be separated from the others and shoved into a situation with a mad person, again. Elsewhere, Jack spends the episode trying to get answers about what Sayid's recent dunk in the Lazarus Pit might have done to him - and in an unusual development, he actually succeeds to some degree. All those years spent dealing with the Others have, apparently, paid off.

As for Sayid, I can't be the only one who seems to be concerned that his iron will doesn't seem to have been resurrected along with the rest of him. Is this part of a larger arc about what is happening to him? Or did the writers just overcompensate in trying to make Dogen seem like a badass? There's a certain bleak irony to watching Sayid begging not to be tortured, but the reactions don't really feel like ‘our' Sayid. Maybe that's the point.

Despite their earlier appearances, Dogen and Lennon do seem to be acting out of the best interests of the Losties they've captured. On one hand, they tried to kill Sayid, but on the other, they saved Jack when he took the pill. Presumably, this isn't out of the goodness of their own hearts, but it does suggest that Sayid is going to become dangerous. After all, they do believe that he's infected. Infected with what?

At this point, it's pretty clear that Dogen is referring to Rousseau's ‘sickness', especially after Claire turns up at the end, having taken Rousseau's role as the island's resident wild-woman. Maybe it wasn't her crew that was sick after all, but her? Either way, it's good to see one of the series' most long-running mysteries finally get a bit of focus!

Meanwhile, in the flash sideways (which, let's not forget, aren't exactly sideways, but also three years back) we get to see what Kate would've done, had she not been stranded. As it turns out, she would still have assumed a pretty major role in Aaron's life, although, once again, Aaron's unusually rapid naming suggests that the two timelines might not be as separate as they appear.

Indeed, it might be just like Lost for us to reach the end of the series and discover that all of the events of the ‘sideways' timeline are actually the result of a cosmic reset that isn't hit at the very end of this series. Jack's mysterious neck cut, Claire's ‘memory' of Aaron - these things didn't exist in the pre-island timeline, so where have they come from if not the ‘real' timeline?

Speculation aside, the action in the sideways-verse probably ranks alongside the better Kate-centric stories, as we're reminded how devious and resourceful - and compassionate - she can be, no matter the situation.

The writers should also be praised for remembering to re-introduce us to Claire before throwing in her appearance as a twist ending, since all-too-frequently, their reveals rely on the audience both remembering and caring about something (or someone) that hasn't had much prominence for months, if not years. Claire's whereabouts have been almost entirely on the back burner since the end of Season 4, so it was a piece of masterful plotting both to bring her ‘back', before they brought her back, and to remind us that Kate did actually return to the island to find Claire.

And while we're discussing the episode's nuts and bolts, it's worth remembering exactly who stole this episode. Suggestions made prior to the series that Sawyer would be going back into ‘Season One mode' are mercifully unfounded. Yes, the rivalry with Jack has returned in full swing, but Josh Holloway sells it with an entirely different edge. The character's swagger is gone, replaced by a mixture of rage and regret fuelled by what he's seen and been through. The scene on the docks was, undoubtedly, a fantastic piece of character development which was and still is unfolding before our eyes.

Slightly less believable is the way Kate blames herself for Juliet's death. Okay, it was a Kate-centric episode, but that's no excuse. At this point, Kate blames herself, Sawyer blames himself, Sawyer also blames Jack, who probably blames himself too. Is there anyone here who doesn't blame themselves for Juliet's death?

Lost has always had trouble with its opening episodes, spending a lot of time re-introducing its threads and setting up the new status quo. Despite - or maybe, because of - its more limited scope, this episode was actually far more entertaining than the opener. And if this turns out to be an average episode for the series, well, that's more than good enough for me.

Check out our review of the final season openers here.