User blog comment:Hyperborean/"The House of Hades" – official expectations blog/@comment-5774152-20130314045212/@comment-3146930-20130315012303

Hard to say. I've most likely read the Percy Jackson and the Olympians series at least 5+ times. The Heroes of Olympus series, I've read the first 2 books about three times and The Mark of Athena twice.