If there's one thing I absolutely love about LOST, it's the dream sequences that crop up every so often.

Wednesday's episode, the mysteriously titled "?" was interestingly full of them, as John Locke and Eko went into the jungle in search of, again, confusingly, the question mark on a map that Locke saw before him. You'd really have had to be paying attention, LOST unfortunately isn't one of those shows you can dip into every so often. On their travels the pair came across the Nigerian Beechcraft made famous by legendary episode "Deus Ex Machina" and more recently Eko's last centric episode, home as it would happen, to yet another hatch. In true LOST fashion, this discovery will turn things on their head.

The episode succeeds because generally, it's that classic LOST formula. Discoveries and revelations are there followed almost inevitably by the further questions and queries that the discovery produces. What also helps is this episode's link to previous episodes, be it via the settings, the details within the flashbacks or even the actions that take place on the island. Furthermore, the character development for Eko himself is deeply satisfying, finally shedding some light on (amongst other things) why he was on the doomed Flight 815. Terry O Quinn, as Locke, is naturally impressive throughout the episode.

With only three hours of episodes left until this season is over, things, are going to get a lot more interesting...