Percy, Annabeth, Jason, Piper, Frank, Hazel, and Leo want to defeat Gaea, but Percy and Annabeth, their smartest and bravest companions are in Tartarus. So Percy and Annabeth try to get out of Tartarus and close the Door of Death. meanwhile, their friends try to close the doors on the mortal side. Then both groups accomplish their tasks and are off to stop Gaea.
This book was amazing! I loved finding out more about each character in certain situations. I found out that Frank is a leader. Also, I never knew what obstacle the characters would have to face. Like the time when Tartarus becomes a body.