Like many children’s book authors, Brian Selznick dreamed of one day winning a Caldecott Medal, the annual award that is the Holy Grail of children’s publishing. Yet when Selznick, a 1988 Rhode Island School of Design graduate who will be speaking at the school on Wednesday, actually won his first Caldecott Medal last month he was, he says, literally dreaming.

“I was fast asleep,” he says with a laugh. “The phone rang — I think it rang two or three times before I picked up. A voice on the other end said ‘Congratulations, you’re the winner of this year’s Caldecott Medal.’ After that, I heard people cheering in the background. Then they hung up.”

Selznick says he knew that his latest book, an illustrated novel about a young boy who lives in a Paris train station and who crosses paths with the pioneering French filmmaker George Melies, was up for the award. Still, the 3:30 a.m. call from the Caldecott’s awards committee caught him by surprise.

“I can honestly say I was completely stunned,” he says.

Fortunately, Selznick didn’t have much time to ponder the unexpected success of his book, The Invention of Hugo Cabret. Within hours, he was on a plane from his home in San Diego (he also has an apartment in Brooklyn) to New York City, where he met with reporters and taped an interview for the Today show. That was followed by a party at his Manhattan-based publisher, Scholastic Press.

A day later, Selznick was back in San Diego.

“All in all, a pretty amazing couple of days,” he says.

Even now, nearly a month after the Caldecott announcement, Selznick seems genuinely surprised by his newfound celebrity. And why not, especially since The Invention of Hugo Cabret breaks just about every rule for a best-selling children’s book.

For starters, there’s the book’s length — more than 500 pages — which is a stretch even for many adult novels. Then there’s the storyline, which somehow manages to encompass everything from Paris train stations to automatons (a type of mechanized doll or robot) to the birth of cinema.

Finally, there’s the unusual way Selznick organized the book — letting his drawings carry most of the story while keeping the book’s written narrative to a minimum.

Asked if his editors ever questioned the wisdom of creating a 500-page picture-book about films, robots and train stations and aimed at young adults, Selznick laughs again.

“Yeah, they probably scratched their heads and wondered ‘What’s this guy up to,’ ” he says. “That would have been my reaction. But in the end they said yes to everything.”

No doubt it helped that Selznick, 41, has a history of taking relatively obscure events and ideas and turning them into popular books. In fact, the plot of The Invention of Hugo Cabret closely follows another one of Selznick’s books, 1991’s The Houdini Box.

In both cases, a young boy encounters a mysterious older man who also turns out to be a famous historical figure. In The Houdini Box, that figure is Harry Houdini, the famed magician and escape-artist who becomes an object of fascination for the book’s hero, a young magician.

In The Invention of Hugo Cabret, the mysterious mentor-figure is George Melies, a French inventor and movie director who created some of the first “moving pictures” in his Paris studio. (Melies also had a puckish sense of humor. In his best known film, a 1902 sci-fi fantasy called Le voyage dans la Lune [Trip to the Moon] a rocket ship crash lands directly into the eye of the Man in the Moon.)

In addition to his movie-making skills, Melies was a talented magician, as well as a maker and collector of automatons — self-powered machines whose shapes and movements mimic those of real-life people and animals. Selznick says he had long been interested in writing a book about Melies, but that he shelved the idea after finding out that Melies also worked as a magician and illusionist.

The reason? One coming-of-age story about a young boy and a mysterious magician was enough.

Selznick says he changed his mind after Melies’ name popped up in a book he was reading — Gaby Woods’ Edison’s Eve: The Quest for Mechanical Life — about the history of automatons. The Melies-automaton connection, in turn, provided the spark for Selznick’s story.

“Georges Melies has always been a hero of mine,” Selznick says. “Many years ago, I saw Trip to the Moon and fell completely in love with it. But it wasn’t until I learned about Melies’ interest in automatons that I started thinking of ways to work Melies, filmmaking and automatons into a narrative.”

In the book, though, it’s the orphaned Hugo Cabret, not Georges Melies, who inherits a broken automaton following the death of his father. Cabret’s attempts to repair the robot — and the friends and discoveries he makes along the way — form the core of the book.

Despite its complicated plot and quirky cast of characters, The Invention of Hugo Cabret has been a hit with both readers and reviewers. Publishers Weekly called the book is “a true masterpiece — an artful blending of narrative, illustration and cinematic technique, for a story as tantalizing as it is touching.” The review in Library Journal praised Selznick for his “intelligence, exquisite images and breathtaking design” and for shattering “conventions related to the art of bookmaking.”

In all, Selznick has written and illustrated a dozen books. Several have won or been nominated for awards, including The Dinosaurs of Waterhouse Hawkins (2002), which earned a Caldecott Honor Award, and Frindle (1997), which won the 1998 Rhode Island Book Award.

Selznick is also much in demand as an illustrator for books by other writers. Walt Whitman: Words for America, a 2004 collaboration with author Barbara Kerley, was cited as one of the year’s “10 Best Illustrated Books” by the New York Times. Other collaborative projects include Marly’s Ghost (with David Levithan) and The Boy Who Longed for a Lift (with Norma Farber).

A New Jersey native, Selznick says he decided to attend the Rhode Island School of Design largely at the urging of his high school guidance counselor. “Basically, she told me that RISD was ‘the Harvard of art schools’ and I, being the naïve teenager that I was, believed her.”

Ironically, Selznick wasn’t drawn to RISD for its high-powered illustration faculty, which (at the time) boasted such luminaries as David Macaulay and Chris Van Allsburg. Instead, Selznick says he spent most of time taking liberal arts classes at Brown University and designing sets for plays at Brown’s Leeds Theatre.

“My parents thought I should get a good liberal arts education, just in case the art thing didn’t work out,” Selznick says. “Fortunately for me, it did work out.”

2008 Caldecott Medal winner Brian Selznick will discuss his work Wednesday at 6:30 p.m. at the RISD Auditorium, North Main Street at Market Square in Providence. The event is free and open to the public.

bvansicl@projo.com