Here’s another dauntless, earnestly brilliant outing from British cinema’s perennial feminist graduate student, Sally Potter. Yes is self-consciously a post-9/11 project, about an overcharged affair between a lovelessly married Irish-American molecular biologist (Joan Allen) and an exiled Lebanese surgeon (Simon Abkarian) now working as a London cook. This would be heady enough even without the rhymed iambic pentameter. Yes, the entire script. Potter supports her verse edifice with the measured curlicues of Philip Glass (among other, less correct-seeming music), and it’s fair to say that her dialogue, at its most distinctive, approaches both Shakespeare and Dr. Seuss—earning demerits for occasional colloquial falsities but mitigating them with verve and fluency. This puts in relief an unintended visual ineloquence: Potter’s abundant, deliberately blurry slow motion seems mostly like a lot of throat clearing. Tellingly, Yes was extrapolated from a short-film version of its most perfectly realized scene, a fierce quarrel in which the lovers discover themselves to be prosecuting a war between cultures. The director doesn’t quite follow through with the toughest work of dramatizing her exalted themes, but, with help from several nimble performances, she stirs up an enchanting aura of urgent topical conversation. Maddening or a masterpiece, depending on whom you ask.