NEW YORK (AP) -- After stops in the ancient worlds of Egypt and Greece, Rick Riordan's ever-traveling mind has booked a flight North.
"The Son Of Neptune," the second of his "Heroes of Olympus" series, comes out Tuesday and already has hit No. 1 on Amazon.com. In the spring, his next "Kane Chronicles" book will be released, continuing his series based on Egyptian mythology. And Riordan will soon get to work on a project he had planned years ago, before his "Percy Jackson and the Olympians" stories made him a million-seller and the Greek gods cool for kids -- a series influenced by old Norse tales.
"The Norse gods are so wild. They have this wild, barbaric energy you don't associate with the Greeks," he said in an interview with The Associated Press over the weekend, seated in a conference room at a Radisson Hotel overlooking Greeley Square in Manhattan, where a prerelease party for "Son of Neptune" would soon begin.
"There are so many fantastic stories and I want to bring Thor and Odin and the other gods into the modern world, just like I did with the Greeks and Percy Jackson," Riordan said. "I'll give the books an urban setting and have young people interacting with the Norse gods."
A Norse series has long been rumored and the author has signed with Disney Publishing Worldwide, his current publisher, for at least three books. Riordan fans, known to remind and pester their parents for months about an upcoming release, will probably have to wait until 2015, the author said. So far, the Norse series is still in the outline phase, and he has "Heroes of Olympus" and "Kane Chronicle" books to write.
In the post-Harry Potter universe, Riordan is a favorite choice for young fantasy readers, and Percy, the boy with a god for a father and the mortal afflictions of dyslexia and ADHD, is a popular idol. "The Heroes of Olympus," a spinoff of the Jackson series, has an announced first printing of 3 million. E-books are the trend for adults, but Riordan, like other children's authors, believes his readers prefer traditional books.
"When I write, I'm still imagining a kid reading it on paper," he told the AP. "I read e-books when I travel, but in general I still prefer holding an old-fashioned book in my hands. There's a special, tactile experience."
A standing-room-only crowd of more than 200 kids and parents turned out for the "Son of Neptune" festival, where the 47-year-old Riordan's plain blazer and slacks looked absolutely human amid actors and fans alike dressed in togas, wreaths, crowns and even a charioteer's helmet. A toga station was set up for those who arrived without costume, and attendees were also presented with pens, posters and a chance to sit in a "party chariot."
A mid-afternoon rainstorm, like a divine tantrum, crashed late enough for performers dressed as Aphrodite, Athena and other gods and goddesses to read from the new book and for medals to be presented to fans quizzed on ancient Greece and Rome. Riordan himself came out to answer a few questions, the kind you don't expect from your average middle-schooler. One noted that Percy's face on the cover of "Son of Neptune" has a scar that shouldn't be possible for a boy dipped in the River Styx.
A boy named Lamont asked Riordan which god he considered the strongest.
"World wars have been fought over this question," Riordan responded.
Another fan wondered if Riordan had seen the film version of "The Lightning Thief," his first Jackson novel.
No, he hasn't, Riordan said, and he probably never will.
"The images from the book you make in your head are always going to be the best images," he said.