Riordan, Rick, <br/><br/>
The house of Hades / 
Rick Riordan. 
 - First edition. 
 - 597 pages ;  22 cm. 
 - The Heroes of Olympus ;  book four. .
 - Riordan, Rick.  Heroes of Olympus ;  bk. 4. .
<br/><br/> Greek and Roman demigods from the Prophecy of Seven must work together to seal the Doors of Death--and help Percy and Annabeth escape the Underworld in the process. 
<br/><br/> Ages 10+. 
<br/><br/><label>ISBN: </label>9781423146728 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Jackson, Percy (Fictitious character)--Juvenile fiction.<br/>Mythology, Greek--Juvenile fiction.<br/>Mythology, Roman--Juvenile fiction.<br/>Hera (Greek deity)--Juvenile fiction.<br/>Gaia (Greek deity)--Juvenile fiction.<br/>Camps--Juvenile fiction.<br/>Giants--Juvenile fiction.
<br/><br/><label>Index Terms--Genre/Form: </label><br/>Fantasy fiction.
<br/><br/><label>Dewey Class. No.: </label>813.6