The bizarrely misconceived Edwardian period comedy "The Missionary," a British film opening today at area theaters, reveals a mystifying lack of judgment on the part of the performer it's meant to showcase -- namely, Monty Python alumnus Michael Palin.

Palin wrote "The Missionary" as a starring vehicle for himself. When the material begins to sputter and then takes an abrupt detour from frivolous bedroom farce into mawkish romantic melodrama, one is obliged to conclude that Palin's deficiencies as a dramatist caused the breakdown.

Observing the finished wreckage in cold blood, it's difficult to believe that such obvious structural and mechanical problems could have been overlooked. Director Richard Loncraine, known here for the compelling psychological thriller "The Haunting of Julia," certainly hasn't finessed the problems, although his graceful, spacious sense of composition gives the film an attractive, formally lulling texture.

The Python comedians have always shown a fondness for overelaborate film production. This tendency carries over into "The Missionary" and threatens to diminish the comic touches, which turn out to be fainter than expected.

For example, the most effective comic invention in the movie is a senile butler, Slatterthwaite, adroitly impersonated by Michael Hordern, who keeps losing himself and callers inside the vast country estate of his employers, Trevor Howard and Maggie Smith as the mismatched Lord and Lady Ames. Ironically, the funny business in the script is always on the brink of getting as lost as Slatterthwaite.

Palin plunges over the brink when he forces the material in a direction it logically refuses to go. His character, the Rev. Charles Fortescue, is a sincere, romantically susceptible young Anglican clergyman who returns to London in 1906 after a decade of missionary work in Africa. He's engaged to a gushing ingenue, Deborah (Phoebe Nicholls), who has acquired a passion for filing paperwork and demonstrates a maddening expertise at deflecting his slightest romantic overtures. Lady Ames, understandably stifled by life in the cavernous mansion with her fatuous mate and absent-minded butler, takes a fancy to Charles, succeeds in seducing him without much difficulty and generously endows the new mission assigned him, a shelter for "fallen women" in the slums of London.

Up to this point there's no reason to apprehend "The Missionary" as anything but a lighthearted, deadpan comedy of seduction. This emphasis even takes a preposterous streak when Charles is shown making a success of the mission, only because he agrees to serve as the house stud for what becomes a harem of semi-converted prostitutes. Lady Ames is supposedly wounded to the quick upon discovering Charles the morning after a typical night's orgy, sprawled in his bedchamber with a trio of mission residents. Without a whisper of serious preparation, we're suddenly asked to believe that something dreadfully serious is at stake in both the clandestine affair with Lady Ames and the continued operation of the seraglio.

Emphatically rejecting the previous humorous emphasis, Palin sends the story off on a bewildering wild-goose chase and at the same time, he gets a feverish attack of sentimentality about his own trifling but agreeable character. The Charles who seemed to blunder into extravagant sexual gratification by being foolishly naive and absurdly obliging to women is now presented as a paragon.

Why the ill-conceived switcheroo? Sheer guesswork suggests that Palin developed a soft spot for his character instead of thinking out the material in coherent, satisfying comic terms.