Mass Effect 2 features a handful of personal side assignments that can help players secure their squadmates loyalty.
Loyalty is one of the most decisive aspects regarding the outcome of Mass Effect 2. Loyal characters are much more likely to survive the suicide mission at the end of the game, as well as certain death later on in Mass Effect 3. Additionally, the player may end up hearing some unique dialogue as part of their reward for being a good friend.
Jack’s loyalty mission is called “Subject Zero” and involves her past under Cerberus.
Mass Effect Legendary Edition: ‘Subject Zero’ Loyalty Mission Guide
Partway through the game, Kelly Chambers will alert the commander to the fact that Jack has been asking for them. Upon going to visit her, Jack will tell Shepard that she wants to go to the facility she was held at in Pragia and blow it to bits. Shepard, Jack, and one other squadmate will then get the opportunity to go checkout the place Jack spent childhood.
Ultimately, as long as Shepard completes the mission with Jack, her loyalty will be obtained. However, they can just as easily lose it during an intervention between Jack and Miranda. We recommend massing some reputation points before completing one or both.
There are spoilers beyond this point—so if you aren’t interested in being spoiled, click away now.
Once on Pragia, Jack will take Shepard around the facility. The team will uncover various audio files relating to her time there, the experiments performed on her, and the status of the other children kept with her. As it turns out, things are pretty different from how she remembers them. That’s to be expected, of course—she was a child. However, the sight does confuse her quite a bit.
According to the audio logs, the other children were fodder for experiments meant to be performed on Jack as she was too valuable of a subject to lose unnecessarily. What she once thought was a window in her cell was actually a one-way mirror. She could see the others playing outside, but they couldn’t see or hear her begging for help. These facts—and others—paint a horrible view of the mental, physical, and emotional abuse she underwent at the hands of Cerberus.
What’s worse: Shepard and the gang aren’t alone on this ruined planet. The Blood Pack are here scouting for scrap and salvage and another surviving experiment has returned with the intent of reviving the program.
Jack can be convinced to spare the other student, called “Aresh,” if Shepard has a high enough Paragon score. Otherwise, Jack kills him, plants, the bomb, and the team escapes Pragia as it blows to bits.