I finished this book and I can't wait for the next! There are many cliff-hangers making it nearly impossible to stop reading the book. At first when I encountered the series, I was like "oh well, this is not a good series." I was defiantly wrong. Once I got into the second chapter of the first book, I could not stop reading! The books got better and better, and the fourth, was the best. Percy and Annabeth are stuck in Tarterus, a place where it is nearly impossible to escape. Meanwhile, the Warship crew is headed toward the House of Hades. There is a slight chance they can get Percy and Annabeth out of Tartus. Also, the Doors of Death are open, meaning once a demigod or god kills a monster, the monster reforms back in Tartus and goes back to the mortal wold. If they close the Doors of Death, stopping the evil titan Gaia, the goddess of earth, will have some hope. If they do not stop Gaia, the wold will be hers forever. I like this book better than any other book I have read. When the next book comes out, I will read it in about a day.