Edward Kitsis, Adam Horowitz
Evan Handler, Bruce Davison and Michael Emerson
Hurley recalls his time in an asylum, where a paranoid fellow patient, Dave, tried to stop him taking his medication. A doctor tells Hurley that Dave is just a figment of his imagination.
On the island
Dave appears to Hurley, trying to convince him that he's still in the asylum. The island, says Dave, is in Hurley's imagination and he can return to the real world by jumping off a cliff. Libby convinces Hurley that the island is real by snogging him, then she has a flashback... to when she was in the same asylum as Hurley (so that's why he thought he knew her!).
"Henry" admits to being an Other. He tells Locke that he let the countdown get to zero... and nothing happened! He also calls the bearded man "a joke" and is much more afraid of someone else in the Others' ranks.
Charlie starts helping Eko build whatever it is he's building.
While this "it's all in your head" stuff has is old hat in telefantasy, "Dave" is enjoyable if predictable hokum. A bizarre opening scene with a newly-health conscious Hurley destroying food strikes a wrong note ("What a waste, you selfish bastard!" is all you can think), but there are plenty of other great moments (Hurley lays into Sawyer... yay!). Libby's slushy speech at the end isn't entirely convincing or satisfying, but luckily the final twist is a corker. Ultimately, though, this is Lost being nowhere near as clever as it thinks it's being.
Charlie: "I saw a polar bear on roller blades with a mango."