One of the castaways is chosen to descend into the mysterious hatch, and Shannon stumbles upon a shockingly familiar face in the jungle. But, as they have discovered during their days on the island, danger and mystery loom behind every corner...even heroes have secrets.

original airdate--September 21, 2005        rating--23.47 million

songs--"Main Title" (Composed by J.J. Abrams)

1. "Make Your Own Kind of Music" by Mama Cass Elliot
2. "Peace Through Superior Firepower" by Michael Giacchino

Flashback--Jack Shephard

1. Jack encounters his future wife, Sarah

Trivia--As part of a recurring theme, "815" is heard as the time of death for Adam Rutherford, 8:15am.