Coyotes howling in the background, a pair of damaged men holed up in a seedy room, the threat of violence—if the plot of Simpatico, playing at A Red Orchid Theatre, reminds you of True West, that’s because the playwright, Sam Shepard, is revisiting themes made powerful in his 1980 play. But while True West ultimately explodes in a devastating finale, not even the ferocious performances turned in by A Red Orchid company members can overcome the limitations of Shepard's unsatisfying script.

The play centers on the troubled reunion of the sleek, brooding Mr. Carter (Michael Shannon, General Zod in Man of Steel) and his one-time partner in the horse racing business, the down-and-out Vinnie (Gus Van Swearingen). They share a shady past that involves swindles, pornographic pictures and a woman named Rosie (Jennifer Engstrom ) who was once Vinnie’s girl but abandoned him for Carter.

Since the unraveling of their partnership, Carter has been supplying Vinnie with regular infusions of cash, funding that’s a cross between blackmail payoffs and hush money. Vinnie, we learn, has possession of scandalous photos of Rosie and a certain Mr. Sims ( Doug Vickers)—images that are so shocking they could destroy Carter if they ever become public. Therein lies one problem with Shepard’s snarled plotting. The photos are presumably of consenting adults. Given their consensual nature, it’s virtually impossible to think of photos so shocking and nefarious they could ruin someone’s reputation.  Moreover, Sims no longer cares whether the images become public or not. So what, precisely, is fueling Carter's breakdown? Implicitly or explicitly, Shepard never tells us. When the True West-esque switchereroo occurs—Vinnie cleans up and becomes focused and driven, Carter curls up in a helpless ball—it comes out of nowhere.

In the end, the reason to see Simpatico isn't for the play itself but for the fearlessly committed cast. Guy Van Swearingen creates a fascinating portrait of a pathological liar grounded in bitterness and barely repressed rage. Mierka Girten is brilliant as an aging hippy who isn't nearly as dumb as she looks. Jennifer Engstrom is a whiskey-over-gravel-voiced femme fatale with powerful claws and incredible, toned legs. And Doug Vickers goes deep to portray an obsessive philosopher of horse sense and thoroughbred bloodlines, though Shannon, who plays menacing well, but can’t quite pull off helpless, is less convincing.

Shannon's celebrity is no doubt a big marketing element for this show—who wouldn't want to see how General Zod is spending his summer vacation? But when Shannon and Van Swearingen are on stage, all the hoopla that inevitably surrounds an Oscar-nominated actor falls away. What's left is no-holds-barred, ego-free, white-hot talent. Shannon may draw audiences in, but he's an ensemble player here, surrounded by a company that makes the novelty of watching a real live movie star become irrelevant in a big hurry.

Simpatico runs through August 25 at A Red Orchid Theatre, 1531 N Wells