Leo Tolstoy once wrote, "All happy families resemble each other; every unhappy family is unhappy in its own way." Not so, says Joe Orton's Entertaining Mr. Sloane, a British play about a family which at curtain's fall is happy, or at least content, in its own very peculiar way. The plot, as summed up in the play's advertising, is this: "Sister wants to sleep with Mr. Sloane; Brother wants to sleep with Mr. Sloane; Mr. Sloane kicks Dada to death." Hardly the kind of situation which makes for happiness, in the natural order of things. But black comedy is Nature spelled backwards, and in this black comedy, happiness is indulging Sister's nymphomania, sating Brother's homosexuality, and removing Dada. Brother and sister blackmail, subdue, and use Mr. Sloane, a two-time killer. As Brother sums it up, "It's been a pleasant morning."

For all its black, and occasionally blue, content, Entertaining Mr. Sloane is an absorbing comedy. Joe Orton spoon feeds his audience shock and grotesquerie, he doesn't throw it in their face. He uses an acute comic talent to show how people lose themselves in petty, selfish, and deviate concerns. The playwright has taken the time he is serving at a leading London prison to construct a careful play which grows progressively grotesque as the characters perceive and accommodate each other's desires.

Laurence Senelick's directing captured the play's tone and succeeded in making this light black comedy touching as well as funny. The sparingly used shock effects and sight gags, the sharp blocking, the distinct footwork which marks each character, the special lighting for climactic moments, combined to give the show a stagey, super-charged quality. The cast included two of the best character actors in Cambridge, Marilyn Pitzele and Senelick himself. They cleverly made their characters a little larger than life, a little histrionic, rather than strictly realistic.

Marilyn Pitzele, Harvard's Rosemary Harris, at first fascinated you with her acting tricks -- she walked in a funny bowlegged waddle, she talked in an impeccable lower class accent, and she wept like a little girl who wanted attention very badly. But her performance was so consistent and thoroughly thought out that she soon overcame any critical defenses and convinced you that she was a pathetic, rather stupid 41 year old woman.

Senelick himself succeeded in playing a septeginarian by chucking the canon of conventional old-man tricks and reinforcing his performance with large doses of pathos, building up a resistance in his audience so that he could administer the biggest dose of all in his death scene. He stunned the house by weaving, choking, and spitting out a farewell mouthful of blood.

The two other performances were only slightly less galvanizing. Leland Moss played the queer brother with restraint, wisely letting the text, not phony mannerisms, establish that the characer was a homosexual. An outlandish swish would have been out of balance with the other performances, all on the quiet side, but Moss might have been a bit more peevish and shrill in his woman-hating moments. Kenneth McBain gave a controlled and droll performance as Mr. Sloane, not perhaps as sinister as he should be, but always the master of his accent and his deadpan. The four actors were acting well together on Friday night and were probably a perfect ensemble by the time the play closed on Sunday. Daniel Chumley's drab set served its purpose and the props man who located a record of "Indian Love Song" should be congratulated.