As Locke recovers from the incident with the blast doors, the situation with Henry heats up. Henry admits to Sayid that he is indeed an Other, but that he will be killed if he talks. So our group becomes jailers in effect, keeping watch over the prisoner of war.
Hurley and Libby's relationship also heats up when Libby takes it upon herself to try and get Hurley into shape. Hurley comes clean and confesses to Libby that he's "sick" - that he has a problem with food - and shows her that he's been hoarding food from the hatch.
Libby encourages Hurley to destroy it, but the moment he does, the pallet is discovered by the entire group, causing Hurley to have a breakdown ...
In FLASHBACK, Hurley's time spent in a mental institution is revealed. And as Hurley's addiction haunts him on the island, so does a friend from his past - a fellow patient from the mental institution that will make Hurley question his very sanity.
Meanwhile, Eko continues building in the jungle and reveals to Charlie that he's constructing a church, enlisting his help.
And when Locke finally confronts Henry, Henry confesses that he did not push the button after he crawled through the vents during the lockdown - but more interestingly, he reveals that NOTHING happened as a result. The world did NOT come to an end, a fact that John Locke is going to have a difficult time digesting …
We are then shown Hurley and his friends from the institution, who we learn is in fact a creation of Hurley's mind. He is standing on a cliff, convinced that the island and everything on it is not real and that jumping is the only way he can wake up. Libby catches him just in time and kisses him, convincing him that she is real, everyone is real. The walk off holding hands.
The last thing we are shown is a flashback, and we see a girl sitting at a table in the institution a little ways away from Hurley. A nurse says, "Here is your medication, Libby." Indeed, it is Libby with brown hair.