In 2054, U.S. Marines Private Jackson "Jack" Mitchell and Private William "Will" Irons take part in an operation to repel a North Korean invasion of Seoul, under the command of Sergeant Cormack. During the firefight, Will is killed and Mitchell loses his arm, resulting in him being discharged from military service. After attending Will's funeral, Mitchell is offered a position in the Atlas Corporation, a private military company, by CEO Jonathan Irons, Will's father, and is also given an advanced prosthetic arm to replace his lost one.
