Man of Science, Man of Faith
The Hatch is explored. A familiar face is inside.
Adrift
The raft survivors struggle to stay alive at sea.
Orientation
The DHARMA Initiative orientation film is discovered. The button's purpose is explained.
Everybody Hates Hugo
Hurley is put in charge of the Hatch food supply. The tail section survivors are introduced.
...And Found
Sun loses her wedding ring. Jin joins a search party.
Abandoned
Shannon's past is explored. The tail section survivors merge with the main group.
The Other 48 Days
The story of the tail section survivors is told from the beginning.
Collision
Ana Lucia faces consequences for Shannon's death. The groups merge uneasily.
What Kate Did
Kate's original crime is revealed. A missing piece of the orientation film is found.
The 23rd Psalm
Mr. Eko confronts Charlie about the Virgin Mary statues. A face-to-face with the Monster.
The Hunting Party
Jack leads a search party after Michael runs off. The Others draw a line.
Fire + Water
Charlie has disturbing visions about Aaron. His rockstar past is explored.
The Long Con
Sawyer pulls off a masterful con to gain control of the camp's weapons.
One of Them
Rousseau captures a man who claims to be a balloonist. Sayid interrogates him.
Maternity Leave
Claire recovers memories of her kidnapping. She searches for a medical station.
The Whole Truth
Sun discovers surprising news. Henry Gale's story is investigated.
Lockdown
Locke is trapped in the Hatch during a lockdown. A hidden map is revealed.
Dave
Hurley sees an old friend from the mental institution. Reality is questioned.
S.O.S.
Bernard wants to build an S.O.S. sign. Rose reveals a secret.
Two for the Road
Michael returns with a plan. Shocking violence erupts in the Hatch.
?
Eko and Locke search for the question mark from the blast door map.
Three Minutes
Michael's time with the Others is revealed. The funeral for the dead.
Live Together, Die Alone (Part 1)
Desmond returns by sailboat. His backstory reveals how he came to the Island.
Live Together, Die Alone (Part 2)
The season finale. The button's truth is tested. Michael makes his choice.