PORTSMOUTH, N.H. -- The most controversial idea in ''The Da Vinci Code," by Seacoast author Dan Brown, is that Jesus Christ fathered a child.

Perhaps the most controversial idea in ''The Norman Rockwell Code," by Seacoast filmmaker Alfred Thomas Catalfo, is the suggestion that bumbling Deputy Barney Fife did the same.

''That's not the most important mystery," Catalfo said, rolling his eyes and smiling Monday at a Portsmouth cafe. There is, after all, a murder to solve.

Primary photography finished Sunday night on Catalfo's short film, which he refers to as a ''comic homage" to Brown's book. The film version of that bestseller comes out May 19, with Tom Hanks as Harvard symbologist Robert Langdon.

''I've met Dan Brown. He's got a great sense of humor," said Catalfo, a lawyer known to his friends as Fred. ''I hate to call it a spoof . . . because spoof implies that you're making fun of it, and we're really not."

Brown's book finds Langdon trying to solve a murder at the Louvre in Paris and uncovering a huge, earth-shattering conspiracy in the process. Catalfo's film focuses on Langford Fife, a bow-tied ''Stockbridge Community College" professor of symbology and the son of bumbling ''Andy Griffith Show" sleuth Barney Fife. The Fifes have come up in the world, apparently, and Langford is asked by police to help solve a murder at the Norman Rockwell Museum in Stockbridge.

Catalfo's friend, actor Mike Walsh, has been polishing his imitation of Don Knotts's Barney Fife for years. Catalfo, Walsh said, was always ''floored" by the impersonation and determined to find a way to use it. Sometime last fall he hatched the ''Rockwell" idea. Filming took place over the last four weekends, including two very cold days at Nubble Light near York, Maine.

Catalfo wrote the script and directs the 20-minute film, also playing a minor role as a detective. Walsh stars, along with Danica Carlson as a cryptologist with the fictitious Quebecois Secret Service. Fritz Wetherbee of WMUR-TV's ''New Hampshire Chronicle" plays the museum curator whose murder kicks off the film.

''Last Sunday night Fritz was laying dead on the museum floor, dressed in nothing but yellow rubber fishing waders, holding a can of tuna in one hand and half a lemon in the other. And he's been harpooned," Catalfo paused to let all that sink in before adding, ''He's a good sport."

Brown, who lives in Rye, has been in a London courtroom recently answering plagiarism charges and could not be reached for comment. The judge on Monday promised a verdict by early April.

Catalfo has not been in touch with Brown about this project or with whoever holds the rights to Barney Fife. He believes fair use provisions in the law allow this sort of parody.

The final scenes were shot late Sunday evening at Three Rivers Farm, a private estate in Dover with vast lawns, a circular driveway, and white-pillared portico. With a sign mocked up near the front door, it became a believable exterior stand-in for the Rockwell Museum.

A couple of borrowed Dover police cruisers were pulled in by the front steps, blue lights revolving. And Fife arrived not in a modern Euro-style smart car, a la Langdon, but in a tiny 1968 Fiat 500 with a bumper sticker that said, ''Symbologists do it in code."

''I can't wait to see the movie," said Kimberly Rawson, director of marketing and communications for the real Norman Rockwell Museum. ''It sounds downright hilarious."

Many museums would not have such a sense of humor about their image. But, Rawson said, ''Rockwell's art work is parodied so often. . . . His work's perennially parodied and reinvented. It's actually a great honor. The museum has never been parodied before, but I guess there's a first time for everything."

The film will now be edited at Atlantic Media in Portsmouth, with Portsmouth's Hatchling Studios providing special effects. Hatchling president Marc Dole has signed on as a producer of ''Rockwell Code," which on Sunday meant nothing more glamorous than lugging lights and equipment around in the cold.

Catalfo hopes to have his film finished in six weeks -- just about the time the Hanks movie opens.

''It's a good piggyback, but I think we would have done it either way," Catalfo said. ''We all really liked the project and we were really doing this for fun."

Hatchling will deliver a ''Da Vinci"-inspired opening credits sequence, in which the letters of the names first appear as anagrams. ''I get 'Hamlet's Carload of Fat' for mine," Catalfo said with a laugh.

The Dover resident followed his father, also named Alfred, into the law and now specializes in personal injury cases.

But his prior career also included near success with a couple of incarnations of his rock 'n' roll band and a year in Los Angeles devoted to music. More recently, he has won several screenwriting contests at festivals, and made a well-liked short called ''Wages of Sin."

The Internet provides a new window for short films. Hatchling will create a website, www.thenormanrockwellcode.com, which should be up in a matter of days.

Catalfo says the film will be posted there when it's finished, hoping to start the same kind of online buzz that attended the ''George Lucas in Love" short a few years ago and, more recently, parodies of ''Brokeback Mountain."

Also in the cards: film festival entries and a public screening or two. And there's talk -- just talk so far -- of making the short film into an independent feature.

One mystery remains. How did Langford Fife get from Mayberry to Stockbridge?

Walsh chuckles and says, ''That is something that if I were a really good method actor I might know."