The Fever Code as being around fourteen, and Aris' partner in building the Mazes. When an outbreak of the Flare spreads to nineteen WICKED staff members, Rachel assists Aris, Thomas, and Teresa in euthanizing them. She does not relish the idea, however, and bitterly states that WICKED's official motto should be "the ends justify the means."
In The Scorch Trials, Rachel is first mentioned by Aris, who explains that she was the only one who cared for him, and they became friends shortly after Aris arrived in the Maze. Rachel could communicate telepathically with Aris like Thomas could with Teresa. From what Aris says, Rachel is Group B's equivalent of Thomas – the second-to-last newbie.However, after Group B escaped from the Maze, a girl named Beth, who seemed to be Gally's equivalent, stabbed Rachel and killed her. The scenario went almost exactly the same as it did for the Gladers, except no one jumped in the way of the knife like Chuck did for Thomas. This leads Thomas to believe that he should have been killed if it were not for Chuck's sacrifice. It is later revealed that Chuck had been under WICKED's control when he jumped in the way.
In the Scorch Trials film, Aris shows Thomas an area where covered gurneys are wheeled into a locked room. Aris reveals that the vents don't go into that room but he has a bad feeling about it, especially since the number of gurneys wheeled in equals the number of people that were called earlier in the day to be "released" from the base to a safer location.
Once Thomas swipes a WCKD personnel's credentials, he and Aris slip into the room, discovering multiple teens from various Mazes hanging from the ceiling. Thomas mistakes one girl hanging limply from one of the machines to be Teresa, but as he pushes her hair aside, Aris discovers that it is Rachel. Aris sadly explains to Thomas that she was called on the first night and that he comforted Rachel that everything would be all right. Both deduce that Rachel is not dead but being kept in a coma-like state as her blood, tissue, and other organs are harvested to produce a cure to the Flare.
In The Fever Code, Rachel is described as having dark skin, dark eyes and tightly curled hair.