At the lunch break, after Dan Brown had just spent the morning on the witness stand defending himself against charges that he plagiarized The Da Vinci Code, a court clerk approached the gazillion-selling American author.

She wanted an autograph.

Standing in the witness box, Brown scrawled his name in her book - the one built on ideas he is accused of swiping from two authors sitting 10 feet away in the courtroom.

"Unusual," said a bemused Brown, a publicity-shy math teacher's son from New Hampshire, who spent five hours on the stand Monday, looking as if he thought his experience in a British courtroom was a bit on the John Cleese side.

Hour after hour, Brown seemed to struggle to answer the questions of the claimants' attorney, Jonathan Rayner James, who, like the judge and the other attorneys, wore an august black robe and a white wig with Shirley Temple curls.

"I'm trying very hard to understand, but I'm not quite sure what the point is here - what I'm being asked," Brown said, clearly taking pains to remain polite and helpful amid a line of questioning as compelling and clear as a toaster warranty.

"It is as if you have asked me to go back five years or 10 years and asked me not only what I got for Christmas, but what order I opened the presents," Brown said.

James asked about the dates and order in which he purchased research books in the 1990s - although not the book from which he is accused of cribbing, The Holy Blood and the Holy Grail - and whether he had turned the sales slips over to his accountant to claim as tax deductions.

Then, with a Perry Mason-like flourish, James asked Brown to examine a photocopy of a sales receipt his team had come across in Brown's copy of a 1971 text of religious history - tucked into page 69, James noted. Brown admitted he was "bad with receipts" and said he would give it to his accountant. That got a laugh from reporters, momentarily stirred from their doodling.

Brown was asked whether it was a "chunk" of writing or a "snippet" that he read from a document about religious history he downloaded from the Internet in the 1990s. James averred, with some force, that it was a snippet, rather than the chunk to which Brown testified. Brown said that was fine, the way a man says he doesn't care if the new curtains are "cream" or "off-white."

But Brown - whose thriller posits that Jesus Christ married Mary Magdalene, that they had a child together, and that the bloodline continues to today - seemed utterly stumped by one question about his research for a book that has sold nearly 40 million copies.

"I couldn't possibly tell you the exact date I learned that Mary Magdalene was not a prostitute," Brown said, allowing just a whiff of exasperation.

Monday's questioning of Brown was largely based on a 69-page witness statement Brown had submitted in December, a remarkable document in which Brown traces his roots as a "preppy geek from New Hampshire" to his status as a wealthy author.

In the statement, released Monday, Brown noted that the first synopsis of The Da Vinci Code he wrote for his new agent was drafted in January 2001 in the laundry room of his parents' winter home in Florida. He wrote it sitting in a lawn chair at a makeshift desk made out of an ironing board.

In his witness statement, Brown said the claim against him by authors Michael Baigent and Richard Leigh - that he lifted "the whole architecture" of their nonfiction historical work - is "absurd" and "completely fanciful."

He said he incorporated some of their book's ideas into his novel, but he had never heard of it until he already established the major themes of The Da Vinci Code" from numerous other books and extensive research by himself and his wife, Blythe Brown. He said he still has never read their entire book.

"I remain astounded by the claimants' choice to file this plagiarism suit," wrote Brown.

He is not a defendant in the case. Baigent and Leigh have filed suit against his publisher, Random House, who, in another twist, also published their book in 1982.

The case has raised copyright questions in Britain, about how extensively a novelist can use ideas raised in other published works. Brown noted that many of Baigent and Leigh's main ideas - particularly that Jesus did not die on the cross - are not in his book.

In his statement, Brown wrote that he grew up in a house with no television on the campus of Phillips Exeter Academy in New Hampshire, where his father taught. On birthdays and Christmas, the Brown children were led on elaborate treasure hunts to find their gifts, following cryptic clues and codes left by their father.

Codes and treasure hunts would become central themes in The Da Vinci Code and Brown's three earlier novels. But Brown originally fancied himself a songwriter and moved to Los Angeles, where those aspirations wilted. It was there, however, that he met his wife and together they began charting his literary career.

Brown also said his novels are populated by characters named for people he's known: his editor, a New Hampshire librarian, a French teacher at Exeter. Some are plays on words: A character named Bishop Aringarosa looks like a villain, but it's really a red herring - and the name is a play on the Spanish for herring and the Italian for red.

Some are anagrams, including Leigh Teabing, an anagram of the names of the two authors suing him. Brown said it was a "playful tribute" to the men for bringing the idea of the enduring bloodline of Jesus "into the mainstream" with their book. "I have been shocked at their reaction," Brown wrote.

In his witness statement and in his testimony Monday, Brown also repeatedly underscored his wife's pivotal role in his novels. As his chief researcher, she would read books and scour the Internet to produce scores of documents for him on subjects ranging from the "sacred feminine" to symbolism in the art of Leonardo da Vinci.

"She often playfully chided me about my resolve to keep the novel fast- paced [always at the expense of her research]," Brown wrote. "In return, I jokingly reminded her that I was trying to write a thriller, not a history book."

Brown said that he had grown up in a home where writing in books was frowned upon - so much so that he said he still feels uncomfortable underlining passages in books, or even signing them.

His wife has no such inhibitions, and frequently marked up texts for Brown to read. James led Brown through a long series of questions asking him to thumb through one of his books and identify which marks were his and which were his wife's.

Quizzed about a handwritten star drawn to highlight one section, James asked Brown if that was the kind of star his wife might make, or whether she would draw some other kind of star, and if so, what kind of star that might be.

"A star," said Brown, sounding a bit weary. "A star like anybody would draw."

Brown is expected to testify for another day and a half. The trial is scheduled to end next week. THE WASHINGTON POST