Secretary Wilson threatens Claire's life, demanding that she drop her investigation. Leon and Shen May rush to the vast subterranean bioweapons lab.

Claire discovers a grim scene at the home of one of the last surviving members of the Mad Dogs Unit. Shen May warns Leon about an ominous conspiracy.

Leon, along with agents Jason and Shen May, embarks on a covert mission to infiltrate a research facility in Shanghai aboard a nuclear submarine.

Now at an NGO in Penamstan, Claire discovers signs reminiscent of Raccoon City. Leon makes his way to the White House, unaware that it's under attack.