Cabin fever inspires three friends to create a series of fitness videos. However, things quickly turn dark as a host of supernatural entities including Slenderman, The Rake, and the psychotic HABIT enters their lives to wreak havoc.

Phil Weston has been unathletic his entire life. In college he failed at every sport that he tried out for. It looks like his 10-year old son, Sam, is following in his footsteps. But when Phil's hyper-competitive dad benches Sam, Phil decides to transfer his son to a new team which needs a coach. Phil steps in to be the temporary coach and immediately begins to butt heads with this dad over this new competition in their lives.