Nico, the son of Hades, and his boyfriend Will, the son of Apollo, travel to Tartarus, the deepest, darkest part of the Underworld, as they attempt to rescue an old friend.

Long ago cursed by the god of lies, a poor miller's daughter has developed a talent for spinning stories that are fantastical and spellbinding and entirely untrue. Or so everyone believes. When one of Serilda's outlandish tales draws the attention of the sinister Erlking and his undead hunters, she finds herself swept away into a grim world where ghouls and phantoms prowl the earth and hollow-eyed ravens track her every move. The king orders Serilda...