Characteristics
She is exceptionally intelligent; in particular she displays extraordinary mastery of computer science. Spending most of her time behind a computer terminal, she is rarely sent on field assignments; however, she has demonstrated proficiency with weapons in Day 4, 5, and 8. She works very well under pressure, yet it is obvious when she is under pressure, and she has always demonstrated a degree of social awkwardness. Despite her lack of social graces, Chloe has gained several friends at CTU and has shown to have a great deal of loyalty to them. She helped CTU Agent Chase Edmunds take care of his daughter from a previous relationship after the child's mother abandoned Chase and their child. She even tried to pass the child off as her own, so as to keep Chase's then-girlfriend, Kim Bauer, from knowing. (Chase did not want Kim to know about his daughter's existence, out of fear that she would leave him.)
She also has a complicated friendship with CTU Agent Jack Bauer. In the beginning, Jack thought of Chloe as an annoyance, though that didn't keep him from using Chloe to engage in unauthorized use of CTU computer resources without their superior's permission. The relationship was one-sided initially, in terms of Jack using Chloe and demanding that Chloe risk her career on her blind faith that Jack was right. Chloe would reluctantly follow Jack's demands and ride out the problems they would make for her with her boss until Jack's requests from her yielded the results that he promised they would.
At the start of season four, her relationship with Jack changed dramatically in terms of her willingness to help him. When a friend of Chloe's was kidnapped by terrorists after accidentally discovering vital information regarding their schemes, Chloe turned to Jack for help. However, Jack shocked Chloe when he told her that he was willing to let her friend die rather than risk letting the terrorists know he was onto them. After several minutes of pleading and begging, Jack gave in and saved her friend. This action led to Chloe becoming completely loyal to Jack, to the point of being willing to be fired from her job at CTU when she refused to stop aiding Jack (who, at the time, was no longer a member of CTU).
By Day 8, the show's final season, she was the only CTU regular from earlier in the series still alive and free. In the last scene of the series finale, Jack tells Chloe that when she first came to work at CTU he would never have expected that she'd be the one to cover his back all these years, before she does him one last favor of turning off the aerial drone's video feed she's watching him on to give him time to escape the country.
Mary Lynn Rajskub, the actress who portrays Chloe, has stated that she believes that Chloe loves Jack, but would never admit it. "She'd want his permission," the actress said.
In the time that she worked with Edgar Stiles, the two had a rather antagonistic relationship. However, there were several moments when they expressed genuine concern towards each other, such as in season four, when Chloe was assigned into a potentially dangerous field assignment and Edgar tried to take her place, or when Chloe refers to Edgar as, "a geek, but a good guy." She also displayed a deep emotional response when she watches him die after exposure to deadly nerve gas.
Chloe also has an ex-husband named Morris O'Brian — a CTU employee, like herself. Chloe and Morris were married and divorced before season 3. During season 5 we learn that Chloe was single, however, her name was already "O'Brian". When Chloe attempts to find him and bring him to CTU to help, he is discovered to be selling women's shoes in Beverly Hills. Morris is quite talkative, charming and flirtatious. But when he arrives at CTU, Chloe is full of resentments, and it is implied that he strayed during their marriage. Nonetheless, in the closing hour Chloe turns to him for emotional solace, which he gladly provides as they leave CTU together at the season's end. On Day 6, Chloe and Morris were together again, though not remarried. It was also revealed that Morris is a recovering alcoholic and that this seems to have been one of the reasons of their breakup.
Before the start of Day 6, she and Milo Pressman briefly dated. This was a source of hostility between Milo and Morris.
Toward the end of Day 6, it is revealed that Chloe is pregnant with Morris's child.
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