User blog comment:SirMoodletonofCanadia/What do you think would happen if Percy had stayed with Calypso??????/@comment-3146930-20110112052000/@comment-3146930-20111210225932

Typhon was dragged down to Tartarus in an earlier chapter and this story was written from a Greek point-of-view (not looking at The Lost Hero as we, the readers, didnt learn about CJ until The Heroes of Olympus). They were defeated like the Camp Half-Blood campers if that gives you some closure.