American Ultra is a fast-paced action comedy about Mike (Eisenberg), a seemingly hapless and unmotivated stoner whose small-town life with his live-in girlfriend, Phoebe (Stewart), is suddenly turned upside down. Unbeknownst to him, Mike is actually a highly trained, lethal sleeper agent. In the blink of an eye, as his secret past comes back to haunt him, Mike is thrust into the middle of a deadly government operation and is forced to summon his inner action-hero in order to survive.