Its been three months since demigod boyfriends Nico di Angelo and Will Solace returned from Tartarus, and there hasnt been a single quest for them in all that time. So, when Nicos half sister Hazel asks them to come to Camp Jupiter to help with an issue, Nico shadow-jumps at the chance to do something.

What Hazel didnt tell the boys is that shes providing a haven for a group of monsters whove escaped the Underworld! Apparently, during Nico and Wills trip to the Underworld, they showed the monsters that they dont have to be evil that the monsters have options.

But then the monsters start disappearing from the camp and its clear a dark force is at work and Nico, Will and Hazel are shocked to find that theyre connected to it . . .