For sixth-form student Grace Becker, The 100 Society is more than just a game; it's an obsession. Having convinced her five friends at Clifton Academy to see it through to the end, Grace will stop at nothing to carry out the rules of the game: tagging 100 locations around the city. With each step closer to the 100-mark they get, the higher the stakes become. But when the group catches the attention of a menacing stalker - the Reaper - he seems intent on exposing their illegal game, tormenting Grace with anonymous threats and branding their dormitory doors with his ominous tag.As the once tight-knit group slowly unravels, torn apart by doubt and the death of a student, they no longer know who to trust.With time running out, Grace must unmask the Reaper before he destroys everything she cares about for ever...