Episode Name: Do No Harm
Episode Overview: While trying to make contact with the outside world from a plane discovered in the jungle tree canopy, Boone Carlyle is critically injured when the plane suddenly shifts and crashes to the ground, so Jack Shephard desperately tries to save his life. The flashbacks in this episode revolve around Jack's marriage to a former patient, Sarah.
Episode Number: 20
Episode Season: 1
Episode First Aired: 2005-04-06