Season 1 (Lost)

This article contains episode summaries for the first season of Lost.

Summary
In the U.S., the twenty-five original episodes of season four aired between September 22, 2004 and May 25, 2005.

Principal Cast
*Only listed in the episodes she appeared in, until "Outlaws" when she became a full regular.
 * Naveen Andrews as Sayid Jarrah (24/25)
 * Henry Ian Cusick as Desmond Hume (25/25)
 * Matthew Fox as Jack Shepard (25/25)
 * Jorge Garcia as Hugo "Hurley" Reyes (25/25)
 * Malcolm David Kelley as Walt Lloyd (22/25)
 * Daniel Dae Kim as Jin-Soo Kwon (21/25)
 * Yunjin Kim as Sun-Hwa Kwon (24/25)
 * Evangeline Lilly as Kate Austen (18/25)*
 * Dominic Monaghan as Charlie Pace (25/25)
 * Terry O'Quinn as John Locke (24/25)
 * Harold Perrineau as Michael Dawson (25/25)
 * Kiele Sanchez as Nikki Fernandez (23/25)
 * Rodrigo Santoro as Paulo Garcia (21/25)
 * Cynthia Watros as Libby Smith (25/25)

Recurring Cast
In order of character appearances
 * Mira Furlan as Danielle Rousseau (5/25)
 * Fredric Lane as Edward Mars (5/25)
 * L. Scott Caldwell as Rose Nadler (5/25)
 * William Mapother as Ethan Rom (4/25)
 * Daniel Roebuck as Leslie Arzt (4/25)
 * Lindsey Ginter as Sam Pace and The Man in Black in the form of Sam Pace (4/25)
 * Jon Dixon as JD (3/25)
 * Michelle Arthur as Michelle (3/25)
 * Kimberley Joseph as Cindy Chandler (3/25)

Main Characters

 * Charlie Pace is a rock star living in Los Angeles, who has had a strained relationship with his alcoholic father (who also happens to be a rock star), especially after Charlie betrayed him. Charlie was married to a woman named Sally, after meeting her backstage at a concert.
 * Libby Smith is a fugitive from the law, but the true reason why she ran is not known until later. After her childhood love dies because of her, she goes to great lengths to retrieve his favorite toy from a bank in New Mexico, but is then apprehended by the Marshal in Australia.
 * Jack Shepard is a doctor whose parents were killed by a drunk driver and could not be saved by the doctors, which inspired him to become a doctor.
 * Sayid Jarrah is a communications officer in the Iraqi Republican Guard who tortured suspects for information. Nadia, his childhood love, got him involved in drugs.
 * Desmond Hume was a Lance Corporal in the Royal Scots Regiment. Desmond saved Penny, his childhood love, and has been searching for her for seven years.
 * John Locke was paralyzed from the waist downwards before the crash, but was healed by the island, which has restored his faith and vigor for life. It's unknown how he became paralyzed, but his father conned him for his kidney.
 * Hugo "Hurley" Reyes is a multimillionaire from Los Angeles after winning the lottery with The Numbers: 4, 8, 15, 16, 23 and 42. However, he believes they are a curse that brings bad luck.
 * Michael Dawson is a construction worker and part-time artist from New York. Susan, his partner, left him and took their son Walt with her. However, after her death Walt was left in Michael's custody, after nine years of separation.
 * Walt Lloyd is a young boy who lived most of his life on the move with his mother. Walt preferred his step-father to Michael, which caused a potential rift between them on the island.
 * Sun-Hwa Kwon is a housewife from Korea, who is married to Jin. Her father owns Paik Heavy Industries and employs Jin to do terrible things, putting a strain on their marriage. Sun plans to leave her changed husband.
 * Jin-Soo Kwon is an employee of his father-in-law's company, which leads him to do terrible things that put a strain on his marriage with Sun, who he only wants to provide for.
 * Paulo Garcia was a chef in Australia who dated Nikki before they broke-up to stay friends. Boone saved Nikki from an abusive boyfriend in Australia, only to be conned for money. Paulo had always loved Shannon, and they had a one-night stand before they boarded the plane.
 * Nikki Fernandez, Paulo's ex-girlfriend, a selfish girl who uses people, including Paulo, her friend, to get what she wans.
 * Kate Austen is a fast food worker from Australia who became pregnant eight months before the flight, but the father left her early in the pregnancy. A psychic prophesied that her baby will be in danger if he's not raised by her alone.