Nico di Angelo and Will Solace were on a quest and had to stop for the night and went inside a cave. Then a goddess named Khione, seeking revenge on Apollo through his son, snowed them inside the cave—and everyone knows Apollo children don’t last long in the cold. So now Will is getting weaker as his light dims further and further, and Nico is powerless as he’s forced to watch his boyfriend slowly fading in his arms.