The Heroes of Olympus: The House of Hades (Book 4), Rick Riordan
THE DEMIGOD CREW OF THE ARGO II is standing at a crossroads. They could return home with the Athena Parthenos statue and try to stop Camp Half-Blood and Camp Jupiter from going to war. Or they could continue on their quest to find the House of Hades, where they might be able to open the Doors of Death, rescue their friends Percy and Annabeth from Tartarus (if they have survived), and prevent monsters from being reincarnated in the mortal world. Whichever road they decide to take, they have to hurry, because time is running out. Gaea, the bloodthirsty Earth Mother, has set the date of August 1 for her rise to power.
Join the demigods of the prophecy as they face their biggest challenges yet in The House of Hades, the hair-raising penultimate book in the best selling Heroes of Olympus series.