The Court of the Dead: A Nico di Angelo Adventure by Rick Riordan, Mark Oshiro

New York Times #1 best-selling authors Rick Riordan and Mark Oshiro collaborate again on a new adventure in which Nico di Angelo teams up with his half-sister Hazel Levesque to protect . . . monsters?

A few months after returning from the depths of Tartarus, Nico and Will agree to join Nico's half-sister Hazel Levesque at Camp Jupiter on the West Coast. She needs their help in managing a situation that the boys inadvertently brought about: the demigods showed the monsters of the Underworld that they have options; they don't have to be evil. Now some of those monsters have taken up residence at Camp Jupiter. Nico and Will are on site, assisting Hazel with a group of "refugees," when one by one, monsters start disappearing from camp. A mysterious dark force is at work, and its plan is to punish all monsters for their past crimes. Things only get worse when Nico, Will, and Hazel learn that they're all connected to it . . .