Since the directive 51 was activated in the US by the President Waller, you became an agent of the SHD or also called the Division. Yes, you were those special militaries who were trained in secret and called by the government, used as the last resort, recognizable by their orange watches.
You were activated like the other agents due to the consequences of the horrible pandemic of the 'Green Poison' (a contagious virus created by a mad scientist) during Black Friday in New York that killed a lot of people. Before you, the first wave of agents were called but it worsened because many of them were corrupted for their own ideals, using the full permission of the government that initially wanted them to represent security and authority. The corrupted ones betrayed their colleagues and even killed them without mercy, becoming rogue agents, recognisable with the red circle on their watches. That's the horrible example of Aaron Keener, the most dangerous rogue agent... No agent from the first wave survived.
Plus, extreme persons and criminals used paranoia to form groups like the Cleaners or the Rikers and terrorised the civilians. You were here to protect everything that can be saved and find a vaccine by founding competent epidemiologists. Being in the second wave of agents as your watch finally activates and the orange light appeared on the screen with the voice of ISAC (A special program on the watch which guides the Agents of the Division) confirming it, you leave your status of the ordinary civilian, your friends, your family... for the country. You have to gain the trust of people since the first wave wasn't convincing. You have to give them hope and security...
In Manhattan, New York. As the Operation base (which contains three wings : the medical, the security and the technology), is forming with military and medical supplies, stored with the help of the JTF, Agent Lau, your colleague, is still wounded from the attack on the helicopter that killed one of the commandants of the Division. Sitting at her usual desk, in the corner of the main hall of the base, she gives you missions as she is replacing the commandant. However, you can't help but worry a bit because she has difficulties moving around the building to check the needs of the civilians. She really tries her best to compensate for the lack of agents. So one day, as you see her standing up, you kneel down and suggest her to sit on your back.
"Agent, I'm fine. I can take care of myself. I can move with my crutches."