The Second Machine War was a massive global conflict that took place after the end of the Truce as covered in The Matrix Online. It began when the people of Zion began secretly constructing New Zion, a second Human city, violating one of the terms of the Truce which was believed to expire within seven years. One of the Machines had discovered them and was destroyed soon after, but not before passing on the information, allowing an Agent to inform the Architect of the situation. Thus commenced the second war between the Humans and the Machines.