The Underneath opens with big pink scuba flippers flopping up and down on a pier. They're attached to the legs of a girl, who's on top of a boy in an amorous beachside writhe, flippers waving clunkily up and down. In moments, at least one of those flipper-encased feet won't be attached to a leg anymore.

And so a show about the evil ocean, or an evil ocean monster, or maybe an ancient evil fish—it's never entirely clear—begins with humping and gore, which is a good precursor to the rest. In a Twin Peaks–like small town, where the local sheriff is honest and heartily mustachioed, where the exhausted diner waitress complains of bunions and reminisces about high school, a developer is planning a huge water park that's expected to rake in the dough. Of course, the development disturbs the old town square, which hides ancient oceanic secrets.

It's hackneyed on purpose—playwright Kelleen Conway Blanchard is drawn to pulp material, injecting it with funny grotesquery and ear-catching details. Take the opening scene, where the two lovers fight over infidelity. "You know I can't help it," whines the guy. He has a deep pain inside himself, "and that makes me want to be inside someone else." She retorts with a list of regrets she has about their relationship:

I regret losing my daddy's car keys somewhere inside that pay toilet where we had the threesome. I regret buying you that pound of amyl nitrate just so you could have very long sex with the girl we met under the overpass who didn't have any fingers.

With those details—the missing fingers, the pay toilet—Blanchard surprises and entertains you anew, even with a predictable plot. But for all its fun language, the show as a whole lacks cohesiveness and has a way of going off the rails. Action scenes get convoluted, characters' motivations switch haphazardly, actors seem lethargic. It's hard to figure out if anyone really gives a shit about saving the town—or even their hot diner-booth sex. Maybe director Pamala Mijatov just needed to give the production stronger guidance.

While the sheriff (James Weidman) and the waitress (Tracy Leigh) seem a little sleepy, smaller characters pick up the slack. Meaghan Halverson as the innocent Winnie Smelter, an adorable pigtailed girl who carries a hissing tentacle around in a jar as a pet, nails her character's cutesiness and then a reversal that is genuinely creepy. John McKenna as your standard pirate-voiced, washed-up sailor-turned-cook spews a winning monologue about his seafaring days, full of "coral nipples" and a woman like a "much-ridden ship." It's these moments, where actors have the freedom to just let loose with strings of Blanchard's perfectly deranged rambling, that make the show worth checking out.

For example: Mandy Price as Kimmi, a future water-park employee practicing her manic recitation of "dolphin fun facts!" that reveals her obsession with dolphin penises. It builds to a climax that includes an exuberantly shouted "Dolphins are full of slits!" Which is a wonderful sentence, both to hear in a theater and, later, to recite to friends. recommended