S02E18: Dave

Libby lends a helping hand to Hurley to support him when he begins to think the island is having a strange effect on him. Hurley begins to see Dave (guest-star Evan Handler, Sex and the City) on the island, who was his friend in the mental institution Hurley was in. Also, Locke's sense of purpose is shaken when the prisoner gives him new information about the hatch.