Arturo manipulated Mónica to get her to sneak a phone from his office, and as soon as she got caught by Berlín (the one in charge of the heist) he ordered Denver (one of the robbers) to kill her. To fake her death, Denver shot her in the thigh, and now she is wounded, hidden in Vault 2, not knowing if she will survive, and in pain from her bullet wound which still bleeds.