Slone is first seen alongside the Apex Predators in the first mission fighting against Tai Lastimosa, eventually over powering him. She is first heard the morning after ordering nearby IMC salvage teams (Salvage Team Gamma to be exact) to capture BT-7274 as a trophy. She is next heard after Cooper takes Kane's radio, informing Blisk that she'd captured three Militia soldiers. Uninterested in their fate, Blisk orders Slone to execute them to which she shortly complies. Slone is not heard again until much later when she learns that both Kane and Ash are dead and that someone had been listening in on their communications.
During the mission where Cooper and BT are interrogated, Slone is shown to have a cold personality and when escaping with the Ark, she destroys BTs Chassis with her customized IonTitan. She is last seen alongside Blisk speaking with General Marder before Cooper arrives.
She is killed by Cooper and BT in the ensuing fight.