Jack

Jack, also known as "Subject Zero", is a notorious criminal whose crimes include piracy, kidnapping, vandalism and murder. She is also a biotic, possibly one of the most powerful human biotics alive, and considered so dangerous she was kept in stasis after she was caught. She is a potential romance interest for a male Shepard.

Jack is voiced by Courtenay Taylor.

Weapon proficiencies

 * Heavy Pistols
 * Shotguns

Dossier
Though her place of birth and origins are unknown, Jack was once the prime subject of a sizable Cerberus experiment on Pragia to enhance biotic potential in humans where she was abducted the moment she was noticed by biotic potential by Cerberus. Referred to as Subject Zero, she was the core of the project, with every successful biotic enhancement applied to her. Many other children were also kept as part of the experiment and many died in trial runs of treatments to ensure that they would be successful on Zero. Any enhancements that proved lethal were not applied to Jack. Her powers eventually grew to such a level that she became a serious threat to the staff, easily killing one by blasting him into a wall. Kept separate from other children, she grew up believing that the entire world was what she could see outside her window and repeatedly screamed herself hoarse while trying to communicate with others through her soundproofed cell. In reality, the window was a one-way mirror. As they were put under the worst of the trials purely to keep Jack alive, the other kids grew to despise Jack as a source of their suffering. This was made only worse by the fact that the only time they ever saw her was when they brought her out, loaded with drugs, and forced her to fight the other children to the death to see how far she had progressed.

Eventually, while being led to another deadly test, the children panicked and rioted. Backed up by their biotics, the riot caused damage to the facility and Zero was freed. At this point her powers had grown so great that nothing could stop her. She would have difficulty remembering those events for the next years in her life, due to her age and the chaos. She would claim the guards and children attacked her, forcing her to kill them all. When she returned recorded logs made it more likely that the children were attempting to either get close to her for safety, as the guards had been ordered to keep Jack alive, or were trying to kill her as a measure of revenge. No matter the true nature of events, Jack killed almost everyone in the facility and managed to get a shuttle off-world, which was picked up by another ship after several days. The crew "used" her before selling her off. After this the Pragia facility was shut down, though many years later the Illusive Man would claim the facility went rogue.

After her escape, Subject Zero went on to live a violent and bloody life. In order to sever ties with her past she took on the name Jack, and reacts violently whenever addressed by her former designation. She has run with various gangs, slaughtered others, was a pirate for a while, crashed a space station into a hanar moon (dubbed vandalism by them), and at one point was a cult member, keeping her head shaved even after her departure.

Eventually, she was captured and imprisoned in the Blue Suns operated prison ship Purgatory. During her time there, she was attacked by a group of guards and prisoners who raped her, despite her efforts at fighting back. Their victory was short-lived however, as Jack personally killed every one of her attackers as soon as she healed. The incident led the Warden, eager for the amount of credits Jack could bring him from Cerberus and other buyers, to lock Jack in cryostasis, for both her and others' safety until Shepard's team came to buy her freedom.

The tortures of her experimentation combined with her criminal lifestyle have rendered Jack a borderline psychopath, with a unpredictably violent nature and a fiery temper. She has an innate lust for combat, claiming to experience "warm feeling during a fight" due to her mental conditioning as a child by stimulating positive feelings whenever she fought without mercy with drugs. She has a tendency to spout profanities constantly in conversation and is very easily provoked. Her body is covered head-to-toe in elaborate tattoos and scars, some remnants of her experimentation, while others mark prisons, kills, and major events in her life. Having been used and abused so many times by people in her life, Jack refuses to trust anyone and is clearly both angered and confused by Shepard's attempts at conversation, being unable to determine what the Commander wants from her.

Yet underneath all this she is still tormented by memories of her past and longs for some kind of closure. She joins Shepard's team in exchange for Cerberus files detailing her experimentation on Pragia after which she asks the Commander to help her destroy the now abandoned facility.

Loyalty
After looking through her files, Jack wants to deploy a bomb at the Teltin facility on Pragia, where Cerberus conducted their experiments on her.

Shepard takes Jack to the facility, unexpectedly encountering Blood Pack mercenaries. After fighting through the mercs, they find another test subject, Aresh. Jack wants to kill him, but Shepard has the option to stop her. The two plant the bomb in Jack's cell, and use the shuttle to escape before detonation.

Once you get back from the loyalty mission, and if you have already secured Miranda's loyalty, then there will be a dispute between Miranda and Jack. If you side with Miranda you lose the option to be romanticly involved with Jack and you lose Jack's loyalty. Jack's loyalty can be regained via renegade/paragon dialogue choices when talking with her after the fight, but the requirements for those choices are very high.

Romance
Shortly after completing the mission at Horizon, during a conversation Shepard has the option to have casual sex with Jack. If Shepard agrees, a feisty sex scene in the small quarters on the engineering deck occurs. However, after the sex scene, Jack refuses to speak to Shepard anymore, telling him that there is nothing to talk about any time a conversation is attempted.

Should Shepard choose to turn down the casual sex option, get to know her first, and pursue a paragon relationship, the result is very different. Jack will eventually soften up and reveal a lot about her past, where on multiple occasions she was taken advantage of when she let her guard down. She also references a time where one partner chose to stay behind rather than abandon her to die, getting himself killed in the process. He left a recording on their shuttle for her in case he died, it talked about the future they were supposed to have, how he planned to build a home for them, about how he loved her and was sorry it wasn't going to happen. This implies a great deal of "survivor guilt" in Jack, from the incident and her time spent on Pragia. She eventually tells Shepard that she needs time to think about everything; it's all very new to her and she isn't quite sure what to do. En route to the final mission, she comes to Shepard in his cabin, tells him she has been thinking a lot about him, and that he's right and she needs someone. Jack gives in, and shows a very vulnerable and emotional side. Tears roll down her face as a tender scene ensues, culminating with her smiling peacefully while they lie together on his bed, and she finally achieves true happiness.

At some point prior to the love scene, Mordin will offer advice to Shepard in regards to his attraction to Jack, mostly concerning the fact that she is likely to either accidentally or purposefully kill him if he keeps trying to get close to her. He will offer to send information packets on biotics and mass effect field manipulation to Shepard's quarters.

Lair of the Shadow Broker
After the completion of Lair of the Shadow Broker, if the player brings Liara aboard the Normandy to catch up, she will ask Shepard what he's fighting for, and if it's a chance to give Jack faith in something more than anger. If the player chooses the "Yes" option, Shepard will say that's she's getting better, relatively speaking. Liara will comment that that's not actually reassuring, to which Shepard will respond that it may not be, but she is important to him. Before she leaves to return to the Shadow Broker Base, Liara will say that she hopes that the two of them will find happiness together.

Trivia

 * Jack periodically yells "I will destroy you!" and "I'll kill you!" when in combat and / or using abilities. This may be a reference to the combat barks used by humanoid enemies in Mass Effect, which became somewhat notorious.
 * If Shepard had casual sex with her, sides with Miranda during her argument with Jack, or if he breaks off their relationship, Shepard will not be able to converse with Jack and she will retort with "Fuck off!" when she is approached. Siding with Miranda will also cause Jack to be disloyal.
 * Jack's name and shaved head might be a reference to the character Jack/Kyra from the Chronicles of Riddick movie series, more specifically the first movie Pitch Black, in which the character was approximately 14 years of age. The two characters also share similarities in that they are both killers and are found in prison, which they both escape from with the help of the protagonist.
 * Jack was voiced by the actress Courtenay Taylor who also voiced the Cathar Jedi Juhani in Star Wars: Knights of the Old Republic.
 * According to the Shadow Broker's dossier on her, she has used the full name Jacqueline Nought on at least one occasion.


 * As with all squad members, Jack has unique dialogue that can be heard at various locations, during missions or assignments, or if a specific squad member is in the selected team.
 * The Shadow Broker has files on Jack which can be accessed aboard his ship.
 * During the car chase scene in the Lair of the Shadow Broker DLC, a wanted poster of Jack can be seen displayed on a large advertising screen above a tunnel. She is holding up the prisoner number 24601