Matthew Fox as <EM>Lost</EM>'s Jack Matthew Fox as Lost's Jack
For lots more on Lost, read our fresh Q&A with Naveen Andrews, check out Jon Hein's look at the Season 4 hype, Matt Roush's preview of the "action-packed" return, use our Strike Survival Guide to get up to speed, and flip through our assorted photo galleries.

Our favorite castaways thus far have been on the island a few months, but for Lost fans, it's been more than 260 days since Jack's super-freaky flash-forward. As the Jan. 31 season premiere (finally) draws closer, TVGuide.com is offering daily profiles — "refreshers," if you will — of the key players in ABC's island-based odyssey. 

Jack, by the "Numbers": When Oceanic 815 crashes onto the island, spinal surgeon Jack Shephard (played by Matthew Fox) quickly emerges as the leader of the castaways; only gradually do we realize that Jack's take-charge attitude is rooted in his true nature as a control freak who has poisoned his relationships with most of his loved ones. The downward spiral of Jack's personal life begins when a woman named Sarah is brought into his ER suffering from massive trauma from a car accident. Jack operates on her and miraculously heals her injuries. Naturally, they fall in love and marry, but they grow apart as time passes and Jack becomes convinced that Sarah has been unfaithful. She eventually divorces Jack, telling him that he can't handle happiness and that he'll "always need something to fix."

After discovering that Sarah called Jack's father, Christian, on his cell phone several times, Jack's paranoia leads him to suspect that his father, who is also a surgeon, is Sarah's new lover. Sarah later tells Jack that Christian merely called her because he was worried about him, but the damage is already done: Christian lapses back into alcoholism and loses his medical license and his reputation when one of his patients dies after he performs surgery while drunk. Christian goes Down Under to drink himself to death, and Jack is forced to collect his body. Jack is an emotional wreck aboard Oceanic 815, but thankfully for him the plane crash gives him a new problem to solve.

Things Got Interesting When..: Jack can't stand not being in control of any situation, and so when he's captured by the Others, it's just a matter of time before he turns the tables on them. When Jack is asked to remove a tumor from Ben's spine, he holds Ben hostage and secures freedom for Kate and Sawyer and passage home for himself. Which would have been great for Jack, if Locke hadn't blown up the Others' submarine.

'Tis Better to Have Loved and Gotten Lost?: Jack appears to have feelings for Kate, but he's devastated when he discovers that she has had sex with Sawyer. Jack grows closer to Juliet, one of the Others, and they form an alliance to cripple Ben's leadership and escape from the island. During the finale, Jack and Juliet finally kiss, but Jack later tells Kate that he loves her, leaving open the question of which woman he truly wants to be with.

Six Degrees of Serialization: The horrific car accident that brings Jack and his future wife together also kills a man named Adam Rutherford, who turns out to be the father of Shannon, another plane-crash survivor. Just before operating on Sarah, Jack goes jogging at a sports stadium and runs into Desmond, who also later turns up on the island. And most importantly, Claire is the illegitimate daughter of Christian Shephard, which makes her and Jack half-siblings (although neither of them knows this).

Jack's Season 3 Story: Frustrated with the Others' control of the island, Jack orchestrates a daring plan to strike back at them and make contact with a mysterious freighter sailing nearby. He succeeds in calling a rescue party for help, but a flash-forward reveals that something has gone terribly wrong: Jack has descended into drug addiction and alcoholism, and for unknown reasons believes that leaving the island was a huge mistake. Now his new problem to fix is finding out how to get back to the island — at any cost.

How Jack Has Us Puzzled: Why does Jack tell Kate that "we were not supposed to leave [the island]"? Did something bad happen to the rest of the castaways that Jack feels responsible for?

Our Wild Prediction: The castaways will have to ask themselves, "Should I stay or should I go?" and ally themselves either with Locke or Jack, whose rivalry will reach a boiling point after a high-stakes table-tennis face-off.

Check out all five of TV Guide's special Lost covers!

Read our Lost character profile for James "Sawyer" Ford, John Locke, Kate Austen, Sayid Hassan Jarrah, Jin-Soo KwonJuliet Burke, Hugo "Hurley" Reyes, Claire Littleton, Desmond Hume, Benjamin Linus, Michael Dawson and Sun Kwon. Catch up with Lost clips in our Online Video Guide.

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