A Theory of Relativity

“Nutty Professor II: The Klumps” is all Eddie, all the time. When the cast list appears at the end of this benighted sequel, the active Mr. Murphy is credited with eight roles. While this surely has its advantages (fewer star trailers to park, no arguments about billing, fewer salaries to negotiate--and to pay), being funny is no longer among them.

This is a waste of talent and a surprise, because Murphy’s ability to simultaneously portray all five members of the hefty and contentious Klump family in two brief but hilarious dinner scenes was the highlight of his first “Nutty” venture and even won him the best actor award from the snooty National Society of Film Critics.

“The Klumps” does show flashes of that original bravura, but the thrill is definitely gone, leaving a disappointing and unpleasant mess in its place. All the Klumps are back, as is Professor Sherman Klump’s ostentatiously nasty alter ego Buddy Love, but several factors combine to make meeting up with them again more of a chore than a pleasure.

On the simplest level, seeing Murphy, helped by three to five hours per day in makeup plus impressive special-effects technology, play elaborate scenes with himself loses the element of surprise the second time around. If familiarity hardly breeds contempt--this kind of wizardry is too much of an accomplishment for that--it does make the proceedings seem more like a stunt than a pleasure.

Also, while no one was exactly clamoring to “Break up the Klumps,” that was the result of the film’s decision to give family members their own subplots. As those original dinner scenes proved, in unity there is strength for the Klumps, and seeing them a few at a time in their own little dramas instead of en masse is less amusing almost by definition. Five Klumps are definitely better than one or two.

Both of these problems might have been overcome if it wasn’t for the film’s decision to compete fiercely in Hollywood’s trendiest contest, the Gross-Out Derby. Putting aside the question of how a film whose repertoire includes erection, flatulence and anal rape jokes qualifies for a PG-13 rating (the MPAA is truly the most mysterious organization since the Rosicrucians), the crude and juvenile sense of humor displayed by veteran Murphy writers Barry W. Blaustein & David Sheffield and “American Pie’s” Paul Weitz & Chris Weitz corrupts everything it touches.

This is a shame, because Murphy brings a surprising amount of empathy to his portrayal of the brilliant but poundage-challenged Sherman Klump, scientist and shining light of Wellman College’s biological research center. And Peter Segal, whose direction is indifferent at best, does seem to want to include some gentler moments. The film’s die-hard tastelessness, however, ruthlessly trumps all its better intentions.

“Nutty II” begins where the first film left off, albeit substituting Janet Jackson for Jada Pinkett in the role of a fellow Wellman professor who is also the sweet-natured woman of Sherman’s dreams. Then, as now, Sherman is on the verge of another staggering discovery, and, then as now, he is locked in mortal combat with his thin evil twin, Buddy Love.

It’s a fountain-of-youth drug Sherman has come up with this time, an elixir so potentially potent that Wellman’s scheming dean (a returning Larry Miller) sells it sight unseen to a grasping pharmaceutical company for $150 million. All Sherman has to do is prove it works at an upcoming public demonstration.

The scientist himself, however, is grappling with a much more personal problem. He may have vanquished the physical Buddy, but the man lives inside him like a monster from the id, causing Sherman to say the most embarrassing things at the most inopportune moments.

Though Sherman clearly needs an exorcism, the professor, either because he’s a man of science or because Max von Sydow was unavailable, chooses another route. He uses an untested method to extract the gene to which Buddy is attached, a procedure that leads to all manner of strange complications, including Buddy’s reappearance as a man with marked canine characteristics. Don’t ask.

Meanwhile, Sherman’s relatives have relationship problems of their own. Papa and Mama are not connecting in the bedroom, while sexually active Granny (Murphy’s most out-there creation) tries her darndest to seduce, of all people, Buddy Love. There is something surreal about seeing Murphy in effect flirting with himself, but, like everything else about “Nutty II,” it’s not as funny as it sounds.

* MPAA rating: PG-13, for crude humor and sex-related material. Times guidelines: considerable raunchy humor involving flatulence, erections and anal rape.

‘Nutty Professor II: The Klumps’

Eddie Murphy: The Klumps, Buddy Love, Lance Perkins

Janet Jackson: Denise Gaines

Larry Miller: Dean Richmond

An Imagine Entertainment presentation of a Brian Grazer production, released by Universal Pictures. Director Peter Segal. Producer Brian Grazer. Executive producers Jerry Lewis, Eddie Murphy, Karen Kehela, Tom Shadyac, James D. Brubaker. Screenplay Barry W. Blaustein & David Sheffield and Paul Weitz & Chris Weitz. Story by Steve Oedekerk and Barry W. Blaustein & David Sheffield, based on characters created by Jerry Lewis and Bill Richmond. Cinematographer Dean Semler. Editor William Kerr. Costumes Sharen Davis. Music David Newman. Production design William Elliott. Art director Greg Papalia. Set decorator John Anderson. Running time: 1 hour, 45 minutes.

In general release.