The wait is over. Markus Zusak, the author of “The Book Thief,” the best-selling World War II drama that was made into a film starring Geoffrey Rush and Emily Watson, has a new young adult novel coming out in October, to be published by Random House.

More than 10 years in the making, “Bridge of Clay” tells the story of Clay Dunbar, one of five brothers whose mother has died and whose father has left them. At the beginning of the book, Clay’s father returns to ask the boys to help him build a bridge on his property in the wilderness; only Clay agrees to do it.

Though Mr. Zusak, 42, began work on the book soon after the publication of “The Book Thief” in 2005, he said in an interview by phone from Australia, where he lives, that he has had the idea for it since he was 19. At the time, he said, he knew he couldn’t write the book. Years later, he found himself still struggling with it.

“When I started writing it, and this was 12 or 13 years ago, I just couldn’t quite feel that it was right and so I just kept trying and trying and trying and then I’d get halfway through and I couldn’t keep going because I thought: ‘this isn’t it.’”