infected with the mysterious transgenic virus Karina is carrying, who escapes in the chaos that follows as Scavengers arrive at the crash site attempting to capture her; the pilot, Stubbs, is killed in the fracas but Mason manages to outfight them. Mason suspects an unusual nature behind the Scavenger attack, as they were not known to possess surface-to-air missiles. Although Karina is highly distrustful of Mason, her former captor, the two of them team up to evade the Scavengers. Mason observes that Karina possesses bizarre powers granted to her by the virus; when experiencing strong emotions, she involuntarily produces an explosive effect that creates mass destruction while leaving her unharmed. Mason and Karina eventually succeed in radioing the Alliance for help, only to learn that Colonel Stockton, the Warden of "the Anvil", has ordered the Alliance to nuke the area and kill everything that moves, supposedly to contain the infection and prevent the spread of the virus. Karina is soon captured by Alliance Security, and Mason finds himself fighting against the very organization he works for. As Mason infiltrates "the Anvil" to retake Karina from Stockton, he finds the Scavengers have also launched a massive assault against the Anvil for revenge; Stockton masterminded the attack on Mason's transport, and that he has paid off the Scavengers to capture Karina for him but he turned out to have used them since he instead had The Alliance capture Karina for himself and refuses to pay them. Stockton is obsessed with battling the Shroud, and wants to use the virus Karina carries as a weapon against them. The Alliance had deemed Stockton's research dangerous, which led him to continue his project in secret. Karina is a weapon created by the Shroud 30 years ago, but she was captured by the Alliance (specifically, Stockton's father) and cryogenically frozen. The virus she carries allows its host to generate massive amounts of energy from their bodies. This energy can be used to power Shroud weaponry and even to create a natural energy shield around the host's body. However, the virus and the energy it produces are also unstable, and hosts have a tendency to explode. When Mason finally confronts Stockton, he learns that Stockton has infected himself with the virus, and gained the ability to produce an energy-shield, as well as the ability to operate a Shroud energy weapon, the "Titan's Fist". The Shroud soon attack