THAT THAT is is, "pontificates the Clown, for such is the wisdom the inhabitants of Illyria wish to hear as they enwrap themselves with madness and wonders in Winthrop House's Christmas production of Twelfth Night. Words grow wanton and fools wise before the play untangles their deceits and leaves us with the feeling that whatever is, isn't.

With shipwrecked Viola masquerading as a page for the Duke Orsino--awaiting the proper moment to reveal her true state--the complicated plot of disguises and counterdisguises unfolds against an admirably uncomplicated set. A charming use of music and a minimum of props set the tone for each act, with extravagant costuming and clever staging making the most of the abundant puns and wit in the play.

The comic scenes delight in visual as well as verbal madness. Heads pop wildly from behind a screen of evergreens during Malvolio's undoing and Sir Andrew Aguecheek mouthes Sir Toby Belch's speech simultaneously from the opposite end of the stage. Even the propmen are carried away, hamming it up as they wander in to change scenes.

Though somewhat less inspired, the courtly side of the plot unfolds with the decorum and irony fitting the overactive imagination of the Count and his sought-after Olivia. As the rejected lover, the Count dons black and hangs his court in purple, while the Lady, mourning her dead brother, parades about in black and purple lace.

Such airs, though, are drunken sport for Sir Toby Belch and company as they plot to entangle the most self-righteous courtier ever created. "Dost thou think because thou art virtuous there shall be no more cakes and ale?" thunders Sir Toby to puritanical Malvolio, who, for his pains, ends up locked up and abused as a madman.

The inevitable result of the disguises and traps everyone indulges in is their complete bewilderment. Only two characters, Viola--who started it all--and the omnipresent Fool, manage to make fleeting passes at reality. David Reynolds deftly plays the Fool's role, a delicate balance weighing the outward frivolity of events against the startling depth of folly. He captures the irony and the sadness of the Clown's state and his success does much to convey the play's more serious overtones.

As a whole, the cast is uniformly strong. Lines are delivered with consistent wit and understanding and all the characters are well-conceived. Although some of them go slightly overboard and become too heavy handed--particularly in the opening and closing scenes--this is a weakness more than compensated for by the quality of other performances. Richard Hope, a bull-headed, red-nosed, raucous Sir Toby Belch, dominates the comic scenes, but his presence is well supported by Linda Dobb's sharp Maria and Locke Bowman's fussy Sir Andrew. Sunny Tufts carries off the difficult part of Viola with grace and Mark Daniels as a quivering chinned Malvolio is inspired.

Although Twelfth Night is not without its weaknesses, they more often come from too much rather than too little effort--words which are almost too erudite in deliverance and grimaces which are too rubbery. Yet even these faults deserve to be forgiven, for, as the Clown would say, sins that transgress are patched with virtue.