LOST - "Dave" - Libby lends Hurley support when he begins to think the island is having a strange effect on him, and Locke's sense of purpose is shaken when the prisoner provides new information about the hatch, on "Lost," WEDNESDAY, APRIL 5 (9:00-10:01 p.m., ET), on the ABC Television Network. (ABC/MARIO PEREZ) CYNTHIA WATROS