David Haller, AKA Legion, is a troubled young man who may be more than human. Diagnosed as schizophrenic, David has been in and out of psychiatric hospitals for years. But after a strange encounter with a fellow patient, he’s confronted with the possibility that the voices he hears and the visions he sees might be real.

When young dockworker Jude leaves Liverpool to find his estranged father in the United States, he is swept up by the waves of change that are re-shaping the nation. Jude falls in love with Lucy, who joins the growing anti-war movement. As the body count in Vietnam rises, political tensions at home spiral out of control and the star-crossed lovers find themselves in a psychedelic world gone mad.

Years after his squad was ambushed during the Gulf War, Major Ben Marco finds himself having terrible nightmares. He begins to doubt that his fellow squad-mate Sergeant Raymond Shaw, now a vice-presidential candidate, is the hero he remembers him being. As Marco's doubts deepen, Shaw's political power grows, and, when Marco finds a mysterious implant embedded in his back, the memory of what really happened begins to return.