Fourteen-year-old Jack Perdu, a prodigy of classical mythology, suffers a near-fatal accident after which he meets Euri, a young ghost who introduces him to New York's ghostly underworld, eight levels below Grand Central Station, where Jack decides to look for his mother who disappeared years earlier.
Orpheus, a mortal rock god, asks Persephone to help him get the love of his life, Eurydice, back from the underworld, and Persephone agrees to ask for Hades help after she is voted most dependable by her friends, a label she doesn't want to have.
