Without warning, on the night of December 23rd, the prisoners inside a Los Angeles jail go berserk, tearing each other apart. Only one is left standing: MIKE (Paul Bettany) . Meanwhile, in the tiny Mojave desert town of Paradise Falls, JEEP HANSEN (Lucas Black going back to his American Gothic roots) awakens from yet another fever dream and begins to draw. His walls are covered with nightmarish visions of fantastic creatures and heroes, including demon lord BELIAL and a mysterious figure... who looks an awful lot like MIKE.Legion is set to star Dennis Quaid, Paul Bettany, Tyrese Gibson, Kate Walsh, Kevin Durand and Lucas Black.
Later that day while Jeep is working on a car the sky darkens. a mysterious black car arrives and the elderly GLADYS emerges. Inside the diner, BOB (Dennis Quaid), pregnant actress CHARLIE (Adrianne Palicki), the LYMANS, cook PERCY (Charles S. Dutton), and suspicious patron KYLE (Tyrese Gibson) watch Gladys eat a rare and bloody steak. Gladys then revels herself to be a hideous creature and attacks Howard and Bob. Kyle kills her with his .45. The diner is surrounded by thousands of flies, the power goes out and the group is trapped inside.
Mike arrives in a police car and distributes weapons to the group. He reveals that they are witnessing the first signs of a war between humans and a horde of the devil's minions. The demon-creatures converge on the diner and attack. The group fights back. While awaiting the next onslaught, Jeep finds a transmission on the radio explaining that all of human kind is under siege by demons. Apparently Las Vegas is the only haven left. Amidst the chaos, Charlie's water suddenly breaks and Audrey helps her deliver a baby boy.