Monica is a blonde American girl on her way to a rave with her friends, Max, Katja and Aaron.
An intoxicated Josh turns his attention to her walking down the hallway during an argument with Kate, causing Kate to leave in frustration. Following his wife down the train cars to apologize, Josh encounters Monica again in a room on the train with her friends, who are all excited for the rave and tease Josh about his age. She was later seen panicking after she came across the next train cart filled with the ravaged remains of its passengers, victims of Ernst's wrath.
She survives the train's derailing, taking refuge in a cave along with the other survivors. After Peter was presumably killed by an unknown creature, Monica, along with Max, Lin, Odessa and Josh venture further into the forest in hopes of finding help. They fall down a slope that plunges them into a swamp. Odessa is forcibly pulled underwater to his death, and in a panic, Monica and the others quickly swim to reach land. The remaining four trek further into the forest, coming across ravaged corpses and a cemetery before reuniting with Aaron, Sacha and Tasha. When the Altered begin to attack, Monica and the other survivors are scattered as they each run for their lives. Unfortunately, she is spotted by Ernst, who decapitates her and throws her lifeless body against a wall.
Monica, along with Max are later reanimated and altered into nothing more then a pair of marionettes, awaiting Josh's arrival at the West Tower. Unable to control their own actions, Monica and Max's bodies are manipulated by the Jesters into fighting against Josh. She alternates between mockery and apology throughout the battle, insisting that the two are being controlled. Ultimately, Josh is victorious, and Monica and Max are killed once again.
In the nightmare realm, it is revealed that Monica and Max were in a relationship. Monica believed that they truly loved each other, when in reality, Max was exploiting her naivety to smuggle his contraband into the United States in her unchecked luggage.