Eventually, the agents find footage of Division agent Aaron Keener going rogue and killing other agents. It is also discovered Keener and other agents who went rogue along with him are assisting the "Last Man Battalion" (LMB), a traitorous private military companythat was abandoned by the government during the evacuation, now hostile to it. Working together, these two groups destroyed the VTOL and killed the Commander to weaken Division operations in New York. Intercepting a signal from the Russian consulate, the agents attempt to rescue Vitaly Tchernenko, a Russian virologist who claims to have information on the Green Poison. However, he is kidnapped by Keener and the LMB before the Division can reach him. After helping the JTF secure supplies and weapons, the JTF and Division agents launch an attack on the LMB's base, the evacuated United Nations headquarters. The agent finds footage of Keener and his fellow rogue agents abandoning the LMB, with Tcherneko as their prisoner. The leader of the LMB, Charles Bliss, attempts to escape in a helicopter, but the agent destroys the vehicle, killing Bliss. Lau informs the agent that with most threats destroyed or weakened, New York is approaching stability, but an unknown signal leads the agent to a secluded laboratory. There, they find Dr. Amherst's remains, having discovered that he has died from exposure to his own virus. They also find a message from Keener, showing he has the technology to manufacture a new strain of Green Poison and intends to do so, and mysteriously tells the agent to explore the center of Manhattan, called the “Dark Zone.” The agent is informed that the information in the lab will further the development of a vaccine and is shown a recovered message from Amherst. In the message, Amherst reveals he engineered Green Poison as part of his eco-terrorist plan to decimate the human race and preserve the planet.