"King Lear," a tragedy as towering as it is ferocious, virtually dares a theater company to reach the top. Few ever do. But the Stratford Festival of Canada, at the Warner Theatre through Sunday, gets higher up the treacherous mountain than most. The second of two productions the Canadians are presenting on their American tour, it will be repeated tonight at 8 and tomorrow afternoon at 2.

The virtues the company manifested earlier this week in "Twelfth Night" -- grace, clarity, intelligence -- are equally evident in "Lear." This is straightforward, uncluttered storytelling, free of a director's bravura touches. But what it lacks in invention, it more than makes up in vigor. And with Douglas Campbell giving a huge performance as the rash monarch who parcels out his kingdom and then finds himself without a home, it can even lay claim to a kind of thundering glory.

Campbell is big in every respect. His body has the corpulence of a Santa Claus; his voice, the majesty of a pipe organ. The chalky expanses of his broad face seem tailor-made for titanic emotions. Here, initially, is a Lear -- swollen by grandeur, rage and indignation. But Campbell's size serves another function. It throws the disintegration of Lear's mind and the breaking of his heart into high relief. We simply do not expect fragility in a man of such proportions, and when the actor's voice turns flutelike and his gestures take on the willowy delicacy of folly, we have a startlingly effective measure of Lear's fall. Either way -- as the colossus or as the colossus' shadow -- Campbell dominates a production, vividly aware of corruption's ways.

Indeed, most of the characters in "King Lear" seem to be trying to outdo one another in villainy. Decency is far outweighed by baseness, unbridled ambition and rampant carnality. Less adroit productions turn the play into a gallery of rogues and its sundry acts of violence into grand guignol. The putrefaction in this "Lear," however, is so persuasively embodied by the supporting cast that the whole world itself seems to be infected. The good do not prevail in the end; they merely win by default, after the others destroy one another.

With her sleek, icy blond presence, Patricia Collins plays Goneril as a cool, hard sophisticate; if the kingdom had a country club, she'd be downing martinis and eyeing the men voraciously at the bar. Maria Ricossa's Regan is a black cat with claws. And while Benedict Campbell doesn't plumb all the nefariousness of Edmund, the apparent trustworthiness of his good looks adds to the evening's ironies. Evil filters all the way down the social ladder -- director John Hirsch has seen to it that even the supernumeraries have the callousness of the morally bankrupt.

The Fool, subtly acted by Nicholas Pennell, knows it. Like Lear, he is at his wit's end. But if Lear rails, there's a sad resignation to this clown's jests, a sweet futility to his huddled posture. Dismay, not antic wisdom, is his refuge. In the tumult and smoke of battle, we spy him briefly, a rope around his willing neck, as he is being led to slaughter. It's as if he understood all along it would end that way.

Those characters aligned on the side of right are less forceful -- perhaps intentionally so. Seana McKenna's Cordelia is wan and gravely despairing; Lewis Gordon's Gloucester, stalwart in his acceptance of evil, seems almost grateful that blindness prevents him from viewing the mounting carnage. Richard McMillan's Edgar, alone, actively subscribes to justice and throws himself into some clankingly robust swordfights with gusto. But there's something spindly about the actor; lacking the physical and moral weight for tragedy, he emerges as a cricket on the dung heap.

Indicatively, the most vibrant color in Chris Dyer and Judy Peyton Ward's costumes is the dingy silver-gray of the Fool's rags. Christina Poddubiuk's set is backed with forbidding wooden panels. Even daylight, as lighting designer Michael J. Whitfield conjures it up, has an ashen complexion. The only illumination comes from the storm that is exploding in the skies and Lear's troubled soul. Darkness prevails, but it is often a magnificent darkness.

King Lear. By William Shakespeare. Directed by John Hirsch; designed by Chris Dyer and Judy Peyton Ward; set, Christina Poddubiuk; sound, Stanley Silverman; lighting, Michael J. Whitfield. With Douglas Campbell, Patricia Collins, Maria Ricossa, Seana McKenna, Nicholas Pennell, James Blendick, Lewis Gordon, Benedict Campbell, Stephen Russell. At the Warner Theatre tonight and tomorrow.