Dave

In WHITE RABBIT, Jack sees Christian on the island. This is an impossibilty because Jack was on flight 815 with Christian's dead body.

In WHITE RABBIT, Christian leads Jack to a cliff that he nearly falls off of.

LIBBY: Hurley, please, you're going to hurt yourself. HURLEY: No, I'm not, because this isn't happening. None of it. I'm just imagining it. This isn't real life. LIBBY: Why would you say that? HURLEY: Because in real life, no girl like you would ever like me. Remember when I said I knew you from somewhere? Well, maybe it's because I made you up? LIBBY: What was the man's name who broke his leg? The day of the crash on the other side of the island, Eko brought a man with a broken leg to me for help. What was his name? HURLEY: I don't know. LIBBY: You don't know. You know why? Because it happened to me. His name was Donald, and I buried him. I buried a lot of people, Hurley. So don't tell me that that wasn't real. And don't tell me you made me up. It's insulting. HURLEY: When you saw me on the beach this morning was I holding a slipper? LIBBY: Not that I can remember, no. [she holds Hurley's face in her hands] Hurley, look at me. I am real. You're real. The way I feel about you -- that's real.

In WHITE RABBIT, Locke finds Jack dangling off the side of the cliff, and helps him back up. Locke then suggests to Jack that perhaps what Jack saw was real.

LOCKE: Why are you out here, Jack? JACK: I think I'm going crazy. LOCKE: No. You're not going crazy. Crazy people don't know they're going crazy. They think they're getting saner. So, why are you out here? JACK: I'm chasing something -- someone. LOCKE: Ah. The white rabbit. Alice in Wonderland. JACK: Yeah, wonderland, because who I'm chasing -- he's not there. LOCKE: But you see him? JACK: Yes. But he's not there. LOCKE: And if I came to you and said the same thing, then what would your explanation be, as a doctor. JACK: I'd call it a hallucination. A result of dehydration, post traumatic stress, not getting more than 2 hours of sleep a night for the past week. All of the above. LOCKE: All right, then. You're hallucinating. But what if you're not? JACK: Then we're all in a lot of trouble. LOCKE: I'm an ordinary man Jack, meat and potatoes, I live in the real world. I'm not a big believer in magic. But this place is different. It's special. The others don't want to talk about it because it scares them. But we all know it. We all feel it. Is your white rabbit a hallucination? Probably. But what if everything that happened here, happened for a reason? What if this person that you're chasing is really here?