Samantha "Sam" works at a crisis hot-line where she listens to strangers and helps them deal with their pain. It's a pain she knows well since the hot-line saved her life once when she lost her sight and didn't know how to live in a world of darkness. On her last night on the job, Sam receives an terrifying visit from one of her regular callers who feels betrayed that she's leaving him. This man is no ordinary caller. He's a sadistic serial killer she's unknowingly been keeping from killing himself for over a year. With only a skeleton on the graveyard shift, there's very little that stands between him and Sam. He's come for her and won't let anything or anyone stand in his way. Will Sam survive the longest, darkest night of her life?