STAGED with Zen simplicity at the Round House Theater, Martin Epstein's playful fable "The Man Who Killed the Buddha" cunningly slips some metaphysics by its audience while they are busy laughing at slapstick pratfalls.

Kenji, a wet-behind-the-ears seeker of truth, leaves his fiance at the altar to trudge the path of enlightenment. At the Doji Shrine he meets Misou Roshi, a shady priest whose questionable wisdom can be bought for a swig of plum wine. Exploitative master Roshi maliciously assigns Kenji an impossible task -- polishing an invisible statue of Buddha.

Time melts and 19 years pass invisibly as Kenji dutifully "polishes space," during which time he is confronted with a series of trials and temptations. Ouushoo, a school chum, flaunts his worldly success and marries Kenji's sweetheart, who herself returns years later and promises Kenji connubial bliss if only he will spit on the Buddha.

After years of devotion to an ideal others find ridiculous, Kenji begins to feel an ecstasy in his work, and finally finds enlightenment -- and soon after, disillusionment. In his surprising, disturbing ending, Epstein makes the unsettling suggestion that man may create his own gods or ideals -- be they sex, success or salvation -- and does away with them when they no longer suit his purposes.

Kenji's final vision of the Buddha is a mixed blessing -- as the priest tells him: "I cannot begin to say which is the more terrible, the things the Buddha reveals to my sight or the things the Buddha withholds from my sight."

Directed by RHT artistic director Jerry Whiddon, the evening rides on the nimble performance of Mark Jaster as Kenji. An accomplished mime and mimic, Jaster conveys both the eagerness of youth and the regretfully opened eyes of adulthood. Richard DeAngelis' dark scowl and gruff delivery, which are becoming a bit predictable, have found their proper place in the role of Misou Roshi.

Round House regulars will rotate in several minor roles. On opening night, Dan Yates turned in perhaps his best performance yet as self-deluding houseboy Majiama, who frenetically enacts a miniature adventure movie, complete with John Wayne and Jimmy Cagney colorings. As unctuous Ouushoo, Whiddon was the epitome of the materialistic churl.

"Buddha" is performed on Richard H. Young's unadorned platform of unfinished planks, with delicately whimsical effects produced by Jane Williams' lighting. White-robed composer/musician Chris Patton sits serenely at stageside, providing unobtrusive Oriental accents on a synthesizer.

THE MAN WHO KILLED THE BUDDHA -- At the Round House Theater through December 22.