Featuring adultery without the naughty bits, a wife-mistress rivalry, and a couple of nursing-home deaths, If I Were You is a screwball comedy for Canadians—not LOL funny, but as crazy as you might expect Toronto to get. Using whip-smart wordplay from writer-director Joan Carr-Wiggin (A Previous Engagement), Marcia Gay Harden does a star turn in versatility. Forget “mash-up”—Harden works many modes, side-by-side and within each other. So polite that she races off in embarrassment after spotting her husband (Joseph Kell) at a compromising lunch with a gorgeous young thing, her Madelyn turns events to her advantage and ends up with three men drooling over her—a nice brains-trumps-cute trick from a starchy matron in sensible heels—even as she fends off Leonor Watling’s charmingly ditzy Lucy. Female bonding rules, but without the programmed feel of Just Between Friends, an earlier prototype. Aidan Quinn is debonair in a small but pivotal role. And a far-fetched plot thread trails the women to an amateur theatrical production, making Madelyn a moving female King Lear. Screwball is logic-immune, of course, and the play does echo the betrayal theme, as well as providing Quinn with what so far is 2013’s best one-liner.