The Heroes of Olympus #4: House of Hades by Rick Riordan

My name is Annabeth, and Percy and I must somehow battle our way through Tartarus to reach the Doors of Death. This trek seems impossible, since we're surrounded by death and despair. I mean we're literally trying to survive among creatures that have died and been sent to the Underworld. Percy and I have slain quite a few of them in the mortal world, and they'd like nothing more than to get revenge against us down here. The Doors of Death are our only hope to escape back to the lands of the living, but more importantly, we must seal these doors before Gaea gains enough power to unleash her monsters and destroy Olympus. But we can't succeed in our quest unless Jason and our other friends are able to defeat the forces guarding the doors on the mortal side.

I still enjoy these books by Riordan, although there are some aspects of them that become annoying. As I've mentioned in other posts about his books, the characters have frequent dreams that are actually visions from other settings or predictions of the future. The effect of this style is that potential surprises in the plot are lost, since readers already have a pretty good idea of what's going to happen. Also, I have a bit of a problem with books being told from multiple points of view, and a half dozen characters are used this time. That wouldn't be a big problem except that the plot jumps around to different settings too. Together, these techniques create some confusion unless you plan to read the book straight through. However, it was sometimes hard to pick up where I left off when I skipped a day or two of reading, as is the case for most of us. For me, a highlight of the book is Bob. This titan helps Percy and Annabeth navigate Tartarus, but Percy defeated him in the mortal world and took away all of his memories. This creates an ongoing problem where Bob could possibly regain these thoughts and turn against the pair of demigods. Bob turns out to be a dynamic character, although what becomes of him at the end is unclear. There are clues, but I still hold out hope. You must first read the previous books in the series if you really want to enjoy this one.