Zack, Carly, Dan, and Sarah have never met, yet have something in common: they all possess a debilitating superhuman sense they can’t control. Sarah's renowned for being a deaf cellist, when in truth she uses her instrument as a shield against maddening noises like a fly a continent away. Dan can see the dust on Pluto, but can only see his hands through a haze of tears. (He’s in therapy.) Carly can smell everything to the point that cocaine is needed to dull the sense, and Zack can break down the ingredients in Col. Sanders’ secret KFC recipe, so he numbs his tongue by drinking - a lot. With the pain and isolation their crippling senses cause, all four haven given up on being normal - and the only thing that keeps them from madness is the hope that they’re not alone.

Their hope is justified when they become aware of each other during a mysterious event that causes them to briefly swap bodies. They set out to meet; however, something else wants to find them, too. A monster in the guise of a teenager that calls itself the Guardian and wants their abilities for itself.

When Dan inadvertently has a flashback to a previous life, they realize that they`re at the end of a roller coaster ride of multiple reincarnations spanning all of history - and that the Guardian has hunted them through each of their lives. To survive in the present, they must relive their brutal clashes with the monster to discover its weakness in the hope of making their next encounter with it the last.