If you were a Bill Plympton character, your skull would be riven open by the experience of watching Cheatin', the animator's first feature since '08. It would throb and pulse as the cleft spread, and rather than blood or lumpish gray, it would be your hurts and memories that spill out, the whole ball of head and hair, like the film, in constant metamorphosis, always folding out of itself into something more. Cheatin' has a narrative, a simple one rendered with boundless invention, and Plympton's signature transformations have never before scored such potent emotions: A ginger beauty, comically voluptuous yet also comically skinny, gets saved from a bumper-car electrocution by a dashing lug of a gas-station attendant — this guy looks like he's got Harry Connick Jr.'s face on John Raitt's body. (Pajama Game fans will fall for him; everyone else will puzzle over some last-century gender politics.)
The pair marry, make brief but eye-popping one-flesh love, and then get caught up in one of those impassioned marriage plots Maupassant used to favor: He finds false evidence that she's cheating, so he cheats for real, scheduling daily assignations at the EZ Motel. There's no dialogue, but there are many tears, most of which, in that sublimely Plymptonian way, shimmer into revelatory new shapes. The tale involves much sex -- inexplicit yet specific, hilarious yet heartbreaking -- plus a couple attempted murders and a bit of crackpot body-snatching magic. The early scenes, of the couple falling for each other, offer more inspired gorgeous wonder than late Malick films, and the emotions are more piercing; the climax, while cluttered with incident, offers the don't-miss-it chance to see a master dream up a pungent freak-out.