This book was actually quite frustrating. I was promised a trip to Rome. It took the majority of the book to actually reach Rome. Once there, it was fun to remember the places they were visiting, where I've also been. I actually wrote a short travel memoir of my trip there.
This is the first time when the full cast comes together. It was interesting to see how they clashed with one another. The two groups kind of did remain, but that was understandable.
I was happy to see Annabeth playing such an important role in the story. It's been a while since I read the first series, but I can't remember her being so prominent even in that. The love story with Percy continues, and they are quickly becoming one of my favourite couples.
In this story, most people have coupled up. This would probably make other books too full of sap for me, but while the relationships were there, the quest, and the fate of the world was more important.
Leo often felt like the odd one out, partly because he was the only single person on the ship, though in a way he seemed to be married to his gadgets. Still, he seemed to be happier tinkering with everything.
The book probably has the biggest cast that I've ever seen in this series. However, all of the demigods and even the satyr played an important role in the story. It would have been easy to side-line someone, but no, everyone had a purpose.
Overall, a good edition. It breaks the usual mould of these books, except for the boss fights at the end. It marks the start of the real quest. The big one, probably the last one.