The Tower of Nero: The Trials of Apollo, Book 5

Parents need to know that Rick Riordan's The Tower of Nero is the fifth and final book in a series that's a spin-off of a Percy Jackson spin-off series. The Percy Jackson and the Olympians series came first, then the Heroes of Olympus. It helps to read them both before digging into the Trials of Apollo series. The storyline picks up after the war at the end of the Heroes of Olympus, and many old favorite characters make cameos or are mentioned, like Percy, Piper, Nico, and Will. And, for extra credit, reading the Apollo chapter in Percy Jackson's Greek Gods helps when our "suddenly mortal and very unhappy about it" narrator, Apollo, recounts key moments of his godly life. A lot is thrown at readers in the way of ancient history, Roman terms, and Greek and Roman characters, so thank goodness for the long glossary at the end of the book. Like the other stories in the series, there's a huge battle near the end with causalities, mostly bad guys. Expect some gore when a boy is forced to cut off someone's hands, but more when the wounds are treated than the actual act. There's also a gory description of someone stabbed in the eye. Apollo gets many bloody injuries. He's stabbed, poisoned, and his nose is broken. He's also nearly crushed and drowned. Twelve kids are repeatedly threatened and manipulated by their foster father, Nero, who also makes many threats to blow up New York City and poison people with a gas that would lead to a painful death. All other content is mild by comparison. There are numerous mentions of name-brand beverages, especially Mountain Dew, and there's some LGBTQ kissing. Apollo's personal transformation over five books is impressive. In Book 1 he's whiny and haughty and feels sorry for himself as a god trapped in a mortal body. By The Tower of Nero, he's willing to sacrifice himself and his immortality completely for his friends and all of humanity.