Rick Riordan is the master of middle grade fantasy. Series like “The Trials of Apollo” began years ago with a book called “The Lightning Thief.” It spawned sequel after sequel after series after series. Now, “The Dark Prophecy” is Book Two in the newest series, “The Trials of Apollo.”

The plot is that Apollo really gets his father, Zeus, angry. To punish Apollo, Zeus sends him to earth as a pimply, flabby teenager. He is tossed into a New York alley, replete with garbage and two thugs out to murder him. Apollo’s adventures in the first book, “The Hidden Oracle,” continue as he and his companions travel to Indianapolis on a mechanical dragon (made like a Lego). They end up in the old railway station, which is called Waystation. Waystation communicates via the two women who live there and run things. Both are retired Hunters (demigod warriors with Artemis, Apollo’s sister), and Waystation shares information telepathically with them. Waystation also creates rooms as they are needed and leads travelers to the rooms that they need to access.

The characters are just as quirky and wisecracking as one would expect from Riordan. But in this series, Apollo shines as the brightest sun of all. In fact, that’s what he calls himself often — the handsomest, the most talented, the quickest, the most musical, and of course, the most divine.

The joys of reading this book include the many, many very clever and humorous “Apollo-isms,” like when he admits to murdering someone:

“I know what you are thinking. But Apollo! You are divine! You cannot commit nurder. Any death you cause is the will of the gods and entirely beyond reproach. It would be an honor if you killed me! …  I like the way you think, good reader.”

Apollo and his friends are on a mission to keep the Triumvirate, a group of three immortal Emperors from Ancient Rome, from destroying the world. Nero is the first emperor that they found in the first book in the series. In this book, the second emperor is unmasked. Along the way, the heroes encounter magical creatures called blemmyae, creatures whose existence has really been illustrated on medieval maps. Riordan makes these creatures absurdly polite. If someone approaches one of them with a question, they are obligated to answer the question before killing the person.

So when they are trying to kill Apollo, and he is lying to the blemmyae about a certain weapon, one asks if he is sure about that. The other elbows her and says, “He just said it was a well-known fact. Don’t be impolite!”

And later, one of the blemmyae, Nanette, says, “if you’re trying to trick us somehow…and I apologize for raising that possibility…” and later they excitedly say, “Then we can rip your limbs off… and trample your bodies into jelly!” The absolute politeness and absolute barbarity make for a very clever and humorous combo.

When Apollo’s companion, a strange demigod named Meg (she’s very strange — must read both books to realize how weird), recites the prophecy after their quest into the Oracle is complete, Apollo is stunned. It is in the form of a sonnet. Apollo kindly explains what makes it a sonnet.

“I had thought the limerick of Dodona was bad. But a full Shakespearean sonnet, complete with ABAB rhyme scheme, ending couplet, and iambic pentameter? Such a horror could only have come from Trophonius’s cave. I recalled my arguments with William Shakespeare.

Bill, I said. No one will accept this poetry. Du-DUH, du-DUH, du-DUH, du-DUH, du-DUH. What sort of beat is that?”

That prophecy is the one that will lead to the third book in the series. But in the meantime, readers of all ages will greatly enjoy this series. It’s supposed to be for older middle grade readers — those in fifth grade through eighth grade. But much of the humor is really aimed at adults, who will enjoy the witticisms that will go right over the heads of the younger set reading the books — especially the music references which will be enjoyed by adult music aficionados.

Another rather daring Riordan twist is that, true to the nature of the Greek Gods, Apollo is bisexual. In fact, in this book, he is attracted to more men than women. Ironically, one of his early lovers is  the evil emperor in the novel. When he first describes the extremely handsome emperor, he says:

“I wanted to whimper. Not just because I still found Commodus attractive after so many centuries, not just because he had a, er, complicated history, but also because he reminded me what I used to be like.” And in a flashback, “We had been friends, more than friends, for almost a month at that point.”

But Apollo, vain, arrogant, self-centered, selfish, does grow in both the first book and this one. Toward the beginning of the story, he is incredulous that two women have given up being Hunters (and being immortal) because they were in love and wanted to be able to live their lives together. Later in the book, he reflects on how they have aged:

“I had never considered that growing older, grayer, and thicker might make someone more beautiful. Yet that seemed to be the case for Emmie. Standing on the table, she was the room’s calm, steady center of gravity.”

Riordan’s Apollo embraces forgiveness when he saves the life of one of Commodus’ fighters after Commodus decides to have him killed. He changes significantly by the end of this second book and even is willing to sacrifice his life for that of a companion.

This reviewer almost wishes that this could be billed as a middle grade/young adult/adult series because readers from all those age groups will greatly enjoy this action-filled, fast-paced, funny fantasy.

Please note: This review is based on the final, hardcover book provided by Disney-Hyperion, the publisher, for review purposes.