plot

"Son of death and curse of flame,

Trek down through the darkness to the land beyond name.

The daughter of doves holds the key,

Through the tomb of eternal sleep.

Queen Eve's cause must be lost,

Lest the earth rot in ceaseless frost."

Leo is a pizza delivery guy, and when he gets an order to one particularly strange summer camp (in winter, of all times), he discovers the key to his mysterious upbringing and a world of mythology unknown.

Nico is helping Camp Half-Blood to accommodate for new campers after the Titan War. When one demigod comes in with a knack for pyrotechnics, and the two are given a quest, Nico realizes he may have to stick around with Leo for longer than just orientation.