Here is a "Lost" plot primer, with a peek at what might be coming:
• Jack Shepard (Matthew Fox), James (Sawyer) Ford (Josh Holloway) and Kate Austen (Evangeline Lilly): The trio at the heart of the story, intrepid doctor Jack, con man Sawyer and tortured bad girl Kate are prisoners of the Others, traded by fellow castaway Michael for his kidnapped son, Walt. ABC released photos of Sawyer in a wooden cell and Jack in a flashback to his doctor days.
Harold Perrineau, the actor who plays Michael, isn't on the cast list this season. Sawyer and Kate face hard labor, while Jack gets a tempting offer from the Others' leader. Producers have said Kate chooses between Jack and Sawyer.
• Desmond (Henry Ian Cusick): Originally a bit player, Desmond surfaced last season as the guy who pushed buttons for years inside the hatch before the Losties discovered him. We know Desmond becomes a bigger fish this season because Cusick joined the permanent cast.
• The Hatch: Before this space was blown up by Mr. Eko (Adewale Akinnuoye-Agbaje) at the end of last season, it was the hub of action. It revealed details of the Dharma Initiative experiment and contained a computer that required regular input to avoid disaster --activating an electromagnet that can pull down a plane, it turned out. We think Mr. Eko and Locke survived the blast.
• The Numbers: Introduced as the digits that Hurley (Jorge Garcia) played to win the lottery, they kept popping up in episodes and were explained this summer in the Lost Experience, an online game. They are the key to a formula predicting exactly when the human race goes extinct. The Dharma Initiative was an experiment aimed at forestalling that apocalypse.
• Sayid (Naveen Andrews), Jin (Daniel Dae Kim) and Sun (Yunjin Kim): The Losties' redeemed Iraqi soldier Sayid pulls together a party of survivors to rescue Sawyer, Jack and Kate from the Others. But his plan endangers the Korean couple, Jin and Sun, who already face a challenging question: Since Jin was believed to be infertile, is he really the father of the child Sun is carrying?
• The Dead Guy: Killed in spectacular fashion while trying to make a radio transmission near the end of the first season, Boone Carlyle (Ian Somerhalder) returns as flashbacks in the mind of John Locke (Terry O'Quinn). ABC lists Somerhalder in the cast for the Oct. 18 episode, "Further Instructions."
• The New People: Kiele Sanchez plays Nikki, who becomes the love interest of another new character played by Brazilian actor Rodrigo Santoro. Elizabeth Mitc (Dr. Weaver's first lover on "ER") also joins the crew
ERIC DEGGANS, St. Petersburg Times