Write Down the Name Gina Gionfriddo. Deft characterization, caustic humor, and well-deployed nips at the American slack moral conscious make “After Ashley,” Ms. Gionfriddo’s acidic puree of modern culture at the Vineyard, one of the necessary shows to see this year. And Terry Kinney’s clever, sleek-but-not-slick production at the Vineyard gives it a first-class presentation.

Playwrights have many tools at their disposal, and one of the best in the box is suspense. Knowing the end doesn’t necessarily ruin the enjoyment of a classic – by now everyone should know that all will not go well for Lear – but it’s cruel to draw the pointiest tooth in a young serpent’s mouth. Ms. Gionfriddo actually deploys a plot that you can’t see coming.

She has a coy way with an audience, puncturing cliches while dropping hints of things to come, or springing surprise guests who up the comic ante. She takes the texture of our culture and forces us look at it in a different light. The gifted designers Neil Patel and Aaron Mooney actually make a fetish of this idea, changing the light source in each scene (a window with a cracked blind, a bank of television lights) to reflect our hero’s state of mind.

Justin Hammond (Kieran Culkin) survived a terrible tragedy at 14: He watched a schizophrenic yardworker murder his young, flirtatious mother, Ashley (Dana Eskelson). Three years later, the fragile teenager should be able to grieve in silence, but the insatiable public maw can’t stop devouring the story. His father Alden (Tim Hopper) has written a successful book about the healing process, and that success takes them to the talk show circuit, where Alden’s version of his wife threatens to replace Ashley’s thorny reality. Justin rages against the hypocrisy around him, but there’s a corrosive quality to prurient pity that he cannot fight.

Mr. Culkin acts with transparent thoroughness. He pads around the stage in his bare feet, completely at home and in possession of the space. Even his tantrums have that gloss of a teenager’s anger – you can still see his latent embarrassment at his own acting-out. It’s a performance for the zeitgeist, and a play for the decade. Neither should be missed.

***

If the realistic satire uptown is sold out, the surrealist take downtown might still be available. Working in a style that could best be expressed as “distractedly Brechtian,” the Undermain Theater arrives with Jeffrey M. Jones’s bizarre tale of a clown, his dog, and the metastatic Land Squid that haunts him.

Sluggo (Tom Lenaghen) is a bad-tempered, foul-smelling clown. Even the flower in his buttonhole looks like it’s bleeding. Sluggo beats his wife Jane (Mary Shultz) and kicks his dog, but though he’s part of a long tradition of Punch characters, he isn’t funny at all. No wonder he’s at a loss: His good angel (Heidi Schreck) has a crush on his brother Steve (Arthur Aulisi) and so barely has time for her charge.

Hapless Steve, though, hasn’t got time for romance, what with his super intelligent, gut-chewing tumor. While he and a policewoman try to wrestle his squid-shaped growth, Sluggo works on his own squid difficulties. If Andy Warhol (a sparkle-wigged Bruce Du-Bose) would just stop bringing him tentacled babies, maybe everyone could get a night’s rest.

Playwright Mr. Jones might be familiar as the co-curater of the “Little Theater” evenings at the club Tonic. His once-a-month revues are like his play – wildly uneven, occasionally hilarious, and best enjoyed after a stiff drink. But though the mayhem might look like a sideshow from outer space, Mr. Jones has exquisite control over his material. He is a master of making strategically unfunny jokes, so Undermain matches him with an intentionally amateurish production.

Pulling his Punch, Mr. Lenaghen gives a marvelously strange performance. His Sluggo looks so dead behind the eyes that he barely registers as human. But the calculated distance he imposes between us could be a primer in Brechtian technique. The material intends to alienate us, to point at the grossness of violent comedy, and Mr. Lenaghen offers a kind of spaced-out callousness to do the job.

When director Katherine Owens really wants her team to be funny, they can be. Most of the night isn’t spent laughing, though. The pace jerks along, always at its most dull when the violence is at its height. Though the company has clearly chosen it as an aesthetic, sometimes alienation can be, well, alienating. Luckily, these are giant squid-type aliens, so even if you drum your fingers through the show, you can always exact revenge from a big plate of calamari.

“After Ashley” until March 20 (108 E. 15th Street, between Union Square East and Irving Place, 212-353-3366).

“Man’s Best Friend” until March 19 (46 Walker Street, between Church Street and Broadway, 212-352-3101).