Fifteen-year-old Kermit Sanders knows grief and its all-encompassing shadows. After losing his beloved older sister in a tragic car accident, nothing quite punctures through the feelings of loss. Everywhere Kermit goes, he is reminded of her. But then Kermit finds a mysterious invitation in his locker, signed anonymously with '-1.' He has no idea what he's in for, but he shows up to find out. Dubbed the 'Minus-One Club,' a group of his schoolmates...