Man of Science, Man of Faith

The hatch is open. A shaft. A ladder. Jack descends first. Below: a hallway, neon lights, a bunker from the 70s. And music. "Make Your Own Kind of Music" by Mama Cass.

A man lives there. Desmond Hume. Alone for three years. He pushes a button every 108 minutes. A code: 4, 8, 15, 16, 23, 42. If he doesn't do it, he says, the world ends.

Jack doesn't believe it. Locke does. The duel that will define the season begins here. The man of science against the man of faith. And in the middle, a button. A simple button.