Kate Austen was on Oceanic Flight 815 handcuffed and in the custody of U.S. Marshal Edward Mars, who had captured her after she'd been on the run for three years. Kate was a fugitive after having taken out an insurance policy on her mother's house before blowing it up with her alcoholic and abusive step-father still inside. She wound up in Australia, living and working on a farm with a man named Ray who gave her up to the authorities in exchange for $23,000.Despite being shackled and handcuffed to her seat on the flight, Kate was able to steal the keys to the cuffs from Mars after he was struck in the head by a piece of luggage that fell out of an overhead compartment. She placed an oxygen mask on him before taking one for herself and survived the crash. Mars, too, didn't die in the crash but was injured. While Kate was checking his injuries on the island, Mars strangled her and she asked Sawyer to kill him. Sawyer botched the job, though, only making Mars' injuries worse, and Jack was left to finish the job.On the island, Kate is attracted to both Jack and Sawyer, which causes a rivalry between the two men. Despite stringing Jack along for some time, she becomes quite jealous when he develops a relationship with someone else. For some time, Jack is the only person in the island to know about Kate's criminal past. Kate is helpful and brave on the island, always volunteering to go on expeditions around the island or to rescue anyone who is in trouble, and putting herself in danger for the benefit of the rest of the survivors.Kate is very protective of Claire, who is pregnant when the plane crashes, and this protectiveness extends to Claire's baby Aaron, who Kate delivered because Jack wasn't around when Claire went into labor. Show less «