Disillusioned, dumped and unemployed on his twenty-fifth birthday, Sam Wilson, a high school mythology teach and self-proclaimed loser, identifies with the attractive, desperate woman poised to jump off the Golden Gate Bridge. He overcomes his own fear to save her just as she morphs into a shrieking demon out for Sam's blood and tosses him from the bridge. Sam crashes into the frigid depths only to undergo what he believes is a near-death experience where he sees the world transformed if he was willing to help. Sam accepts the challenge in exchange for his life. With his assent, he is rescued by his guardian angel who entangles Sam in a dangerous quest where he must find and silence a demonic sound and bring exiled angels back to San Francisco before demons destroy the city and ultimately, mankind.