Outgrowth follows the story of an Oregon family whose summer camping trip goes horribly wrong when a colony of ants infected with an invisible fungal agent follow an unwitting family member back to their secluded yurt in the Willamette National Forest. Things go from bad to worse as the fungal assailants infect one member of the family after another until finally, the family’s skeptical daughter (Evan) see’s the horrible truth with her own eyes and attempts to spirit the remaining members of her family away from the terror unfolding in the woods. But is she fast enough to escape?