Pity the poor fan of Rick Riordan's popular series for adults about Tres Navarre, a Texas private eye with a PhD in medieval literature and an enchilada-eating cat. Beginning with the first book, Big Red Tequila, in 1997, readers could reliably count on a new mystery almost every year.

   Then Riordan's sons persuaded him to write down the bedtime stories he had concocted for them with characters from Greek mythology, one of the subjects Riordan taught at a San Antonio middle school.

BY SUE CORBETT
Do you have a kid who would like to introduce Riordan at his Coral Gables appearance? Find out how in Sue's Growing Readers blog. Share your recommendations for young readers in our Kids' Books forum.

   Five million Percy Jackson and the Olympians books later, Riordan is glad that Haley and Patrick, now 14 and 11, insisted.

   "As soon as I began, Percy's voice came out very clearly and strong, and I knew I was on to something," Riordan said in a telephone interview before starting his tour to promote The Last Olympian (Hyperion, $17.99, ages 10-up), the fifth and final volume in his series starring the dyslexic, ADHD son of Poseidon. "I also had a sense of urgency. I felt I had a big idea and I really needed to pin it down before somebody else did."

  Maybe Riordan will get back to his detective -- eventually.

  But Percy Jackson, who lives in a modern-day Manhattan where the ancient gods of Olympus continue to fall in love with mortals and produce half-god children, has firm control of the author's attention. In Vancouver, director Christopher Columbus is filming the movie version of the first book, The Lightning Thief (scheduled for theatrical release in February 2010).

IF YOU GO

Rick Riordan will make two South Florida appearances on Sunday, May 17:

• 1 p.m., Borders bookstore, 12171 W. Sunrise Blvd., Plantation. No tickets required, but you will need a wristband to get in line for an autograph. The signing ends at 3 p.m.

• 5 p.m., Coral Gables Congregational Church, 3010 De Soto Blvd., Coral Gables (across from the Biltmore Hotel), sponsored by Books & Books. Tickets are required for this event and can be obtained at any Books & Books location with the purchase of The Last Olympian (one ticket per copy). There will be a waiting room at the church parents or chaperones who do not have a ticket.

Follow Riordan on Twitter at http://twitter.com/camphalfblood.

  Riordan is winging his way around the United States to talk about the last book, with two stops in South Florida.

  The kids who propelled Percy to the bestseller list have mixed feelings about The Last Olympian -- before they even finish it.

  George SanJuan, a seventh-grader at The Nativity School in Hollywood, got his copy as soon as the book went on sale last week. But he's making a deliberate effort to stop himself from racing through it.

  "I'm trying to read it as slowly as possible to make it last longer," George said. ‘‘I really don't want the series to end."

  The Last Olympian does not disappoint.

  It finishes the series with a splashy, colorful blast. The action takes place during the run-up to Percy's 16th birthday, an occasion he's not looking forward to since a prophecy suggests he's going to die that day.

   Probably during a battle, since Percy, Annabeth, Grover and the rest of the half-bloods are trying to stop a hostile takeover of Mount Olympus (which you can reach through a
special elevator in the Empire State Building) by the titan Kronos.

   Much mayhem ensues as Kronos' army clashes with Percy's gang in midtown Manhattan. Pigs fly, rivers talk, even the New York Public Library's stone lions come to life and join the combatants. In fact, it seems like every monster in the Greek pantheon is unleashed, including many you have probably never heard of but which Riordan says he took straight out of Greek mythology.

  "One of great things about writing this series is that I've gotten to delve into some of the legends that have been forgotten," he said. "There are some fabulous monsters out there that have lain dormant for thousands of year, and I'm only too happy to dust them off and throw them at Percy."

  Percy's adventures have revitalized an interest in classic Greek mythology. Riordan reports a number of schools have incorporated The Lightning Thief into their curriculum. High school teachers are using the books as "a gateway into Homer's Iliad and Odyssey," he says. "I've had letters from librarians who said, ‘My 200s [the Dewey Decimal classification for world religions] were gathering dust, and now I can't keep them on the shelf."

   Fortunately, though The Last Olympian ties up nicely, it also hints that we haven't spent our final hours on the grounds of Camp Half-blood, where the demi-gods train.

   Riordan confirms this. In the current series, the characters "go to Camp Half-blood but they never stay there. They're always gallivanting across the world," he said. "I've had a lot of letters from readers who want to know, ‘What exactly goes on there? What about this cabin, or this character?' So though I wanted to have a strong ending to Percy's story, I also wanted to mine the same material for a spinoff."

  So much for getting back to the private eye. Looks like Tres Navarre will have to find a case involving a Cyclops if he wants Riordan's attention anytime soon.