NEW YORK - Audiences at Wednesday's matinee performance of "War Horse" likely never noticed a very special actor who was making his Lincoln Center stage debut.

Best-selling author Michael Morpurgo, who wrote the book the Tony Award-winning play is based on, was part of more than a dozen actors watching the auctioning of the horse Joey at the top of the show.

The author, who made a similar crowd scene appearance in the London production of "War Horse" and was an extra in Steven Spielberg's movie version, didn't have any dialogue and didn't appear again until the curtain call a few hours later. The only hint he was there was when the auctioneer called out for "Mr. Morpurgo."

"They hide me away," the 68-year-old writer said with a smile during a backstage interview, still wearing his velvety Edwardian-era coat. "For me, it's a wonderful privilege for me to be connected to this whole way that theater works."

In some ways, Morpurgo's New York professional acting debut was more meaningful than the others: His father -- the Canadian actor Anthony van Bridge -- twice appeared at Lincoln Center in the 1960s.

Morpurgo, who has written more than 100 children's books, had come to New York after visiting the Canadian cast of "War Horse" in Toronto, which starts up in February. The chance to step where his father stepped years ago was too irresistible to turn down.

"I thought, `I've got to go and be in the same place.' Isn't it silly?" he said. "I love full circles."

Van Bridge, a respected actor in Canada who was a fixture at the Shaw and Stratford festivals, left Morpurgo's mother after returning from World War II to find she'd rather be with another man. Morpurgo and his father eventually reunited when he was in his 20s; he now calls him a "sweet, kind man."

"War Horse" premiered at the National Theatre in November 2007. After two sold-out runs, it moved to London's West End in March 2009, where it continues to play at the New London Theatre. It opened at Lincoln Center this year and won five Tonys, including best play, and a U.S. tour will open in Los Angeles in June and travel to 19 cities, including Philadelphia, Dallas and Minneapolis.

Morpurgo, a former teacher who discovered his love of storytelling in the classroom, likes to visit each cast to talk about the roots of his best-selling 1982 children's book, which tells the story of a horse that has been enlisted to fight for the English in World War I. The show, adapted by Nick Stafford, is visually stunning, thanks to creative work by Handspring Puppet Company.

At one point during the interview, Austin Durant, who plays the auctioneer Chapman Carter, comes in to ask Morpurgo to autograph a volume of "War Horse" for his mother, Doris, as a Christmas present.

"Auctioneer, you were wonderful," Morpurgo told him.

"It was great!" said Durant, beaming. "Well played."

Morpurgo, who was Britain's third children's laureate, laughs about the incredible path his book "War Horse" has taken. When it was first published, it was largely ignored and for years never sold more than a few thousand copies a year, though his wife, Clare, thinks it is his best.

Then in 2005, Tom Morris, a director at the National Theatre, was looking for a way to create with Handspring Puppet Company a family friendly work. Morris' mother suggested "War Horse" after reading a second-hand copy.

Now it's been translated into 33 languages and has more than 500,000 copies in print.

"It's the same bloody book," he said, laughing.