After Layla is banished from school for asserting her beliefs, Ava and her friends travel to the underworld to rescue Layla and uncover the truth about their fiendish ancestors.

Ava Baldwin is ready for her second year at the Accademia del Forte. Now that she knows that her fellow classmates, descendants of the so-called Greek monsters, have been lied to by the Olympians, she's ready to help them uncover their ancestors' true stories--if only she can stay out of the way of the new headmaster, Perseus. But laying low is easier said than done, especially when Perseus seems intent on trolling Ava, making it impossible to control her anger. When Perseus banishes one of her friends, Ava must lead a rescue party on a whirlwind adventure from the Stygian Marsh of the underworld to the ice caves of Mount Etna with Ares and the spirits of violent death in hot pursuit. But the gods won't be tricked so easily this time...