Percy Jackson had gleaned a couple of things from the return of Nico di Angelo in his life: One, everything is better when you're drunk. Two: cigarettes taste bad but could be worse. Three: he might possibly be the teeniest-tiniest bit unequivocally gay.

Percy and Nico have always been best friends. Over the years, Nico has developed feelings for his best friend. Planning a Halloween party with their friends at Percy's family's vacation house, Nico hopes to confront Percy about them. The problem is, they aren't alone in the woods. There's something in the house, and now Percy and Nico must try and survive.

As Percy's wedding approaches, he thinks back on someone from his past, and the biggest mistake he had ever made.