TY  - BOOK
AU  - Rick Riordan
TI  - The House of Hades (Heroes of Olympus, Book 4) 
SN  - 9781423146728
U1  - FIC/RIO/2013 
PB  - Disney-Hyperion
N1  - Age Range: 10 - 12 years
Grade Level: 5 - 9
N2  - At the conclusion of The Mark of Athena, Annabeth and Percy tumble into a pit leading straight to the Underworld. The other five demigods have to put aside their grief and follow Percy's instructions to find the mortal side of the Doors of Death. If they can fight their way through the Gaea's forces, and Percy and Annabeth can survive the House of Hades, then the Seven will be able to seal the Doors from both sides and prevent the giants from raising Gaea. But, Leo wonders, if the Doors are sealed, how will Percy and Annabeth be able to escape?
ER  -