James Urbaniak, in 1950s glasses and a loose-fitting suit, enters in total darkness. He tries to strike a match, which goes out. “Nice to see you,” he tells us. He reads a bit from a paper. At no point have we been able to make out anything in the darkness.

It’s handy to have this visual metaphor for “Thom Pain (based on nothing)” upfront – we’re uncomfortable, we’re laughing, and we haven’t got the first, foggiest clue what’s going on. Describing Will Eno’s bizarre monologue, sussing out its intent, context, or parameters, might just be impossible. Engage it in debate? I’d rather wrestle an eel. But I can recommend it fervently. It’s difficult to figure out why the play is so charming – just as it is with James Urbaniak, the slippery performer – but it will get you all the same.

Mr. Urbaniak’s rambling, ranging monologue constantly subverts itself. If he smiles particularly sweetly, he’s sure to curse us in the next moment. If he sets up a magic trick, he is bound to disappoint us. In fact, the entire play feels like a shaggy-dog story – all set-up, no punchline. Just how long Mr. Urbaniak’s delivery of Mr. Eno’s text can string out the suspense turns into the suspense itself. How much “nothing” can we take?

Though our narrator avoids telling us how he got the name “Thom Pain,” pain certainly seems to be his closest companion, whether it’s a scar from childhood or a recently ended relationship. Mr. Eno’s narrator is like the boy in one of his stories who wanders into a bees’ nest. Confused about whether the bees are stingers or salve, he rubs the insects into his hands, trying to stop the pain bubbling up from inside him. Mr. Urbaniak’s unhinged narrator may be trying the same trick with us – bringing up his worst memories, hoping they will make him feel a little better.

Mr. Urbaniak must have a magic portrait in his attic. He doesn’t look a day more mature (or more trustworthy) than he did in Hal Hartley’s “Henry Fool.” His hair still flops endearingly, his smile is still dented and a little mad looking. He still seems too slight to mean us any harm. At one point, he can’t even persuade the light operator to illuminate his chosen corner.

But when director Hal Brooks lets him into the audience, his smile gets a shade more feral, and suddenly the whole thing feels dangerous.

Delicious. So see it!

***

At Theater Row, down into the bowels of the complex, the Grass Arena company has mounted Kirk Marcoe’s “I See Fire in a Dead Man’s Eye.” Mr. Marcoe also directs, so all blame can, I think, rest squarely on his shoulders. Extorting cliches from several genres, Mr. Marcoe’s piece squashes the efforts of several fine, nervy actors. As Harrison Ford once said to George Lucas, “you can type this s—, but you sure can’t say it.”

The “dead man” of the title is Bob Wright (David Chandler), a near-vegetable, bedridden and out of communication with the world. He seems beyond contact, though he can still make a palsied gesture so that his wife (a fluttery Jennifer Van Dyck) will give him a cigarette. Of course, we can hear his furious inner monologue. Preoccupied with memories of the war and his increasingly badly behaved son Tim (Matthew Stadelmann), Bob actually has rather a lot to say.

Tim has become a serial seducer of other teenagers, crossing racial lines his father wouldn’t dream of. The whiter of the two girlfriends, Vicky Perez (Jessma Evans) is in the ascendant, which sets jilted Bertha (Tamara Bass) against them both. Her mother, also the Wright’s maid (Cherene Snow) discovers the whole team in a drunken sprawl, which leads to simultaneous recriminations in every corner of the house. Mr. Marcoe clearly intends this to be a zany experience, but instead all the overlapping dialogues ensure no one conversation can make sense.

Elsewhere these actors have delivered appealing performances, so the vast irritation they induce here cannot be laid at their doors. Only Ms. Evans emerges with her dignity intact, though it might be because she has the fewest lines. For some idea of the vacuous, painful situations the cast finds themselves in, one need only look at the final tableau.

After a moment of lucidity, Bob has told his wife that he admires her bottom. As the music swells, she displays said feature to him, and he reaches toward it and the lights fade. You get what you reach for.

“Thom Pain” until April 3 (103 E.15th Street, 212-239-6200).

“I See Fire” until February 20 (410 W. 42nd Street, 212-279-4200).