Since her first play stunned New York audiences four years ago, Annie Baker, 31, has gone from obscurity to acclaim. In that time, critics have scraped away at her plays, trying to unearth what makes them so rich, so unsettling and, most of all, so real. Never mind that Baker herself rejects such labels as realism and naturalism, and that there's much in her plays that's more surrealistic than anything else. Take, for example, a moment in Third Rail's deeply humane and quietly unnerving production of The Aliens. KJ (Isaac Lamb), a bearlike 30-year-old who lives at home and drinks shroom tea, tells a story. At age 5, he was obsessed with the word "ladder" and repeated it incessantly, until his mother let him shout the word as often and as deafeningly as he needed. Lamb delivers a monologue—if it can be called that—composed of that single word. I began counting the number of repetitions and then lost track, finding myself hypnotized and horrified and heartbroken. It's sublime and sorrowful, wonderful and terrible.

The Aliens, as with much of Baker's work, is constrained but not contrived. It's set in the scruffy backyard of a cafe, where KJ and Jasper (Chris Murray) gather amid the trash cans and busted bicycles. After Jasper, a Bukowski-reading chain-smoker who's writing a novel, kicks over a chair, teenage employee Evan (Bryce Earhart) tries to shoo them away. But KJ and Jasper can sense how Evan yearns to belong—they're loners themselves, after all—and they welcome him. It would be easy to say this irreverent yet warm duo teaches Evan about life and identity, but what unfurls is far more intricate, and far more tragic, than that.

Under Tim True's confident direction, the actors create intensely empathetic characters. Lamb, in a wig right out of Wayne's World, nails the gentle comedy as well as his character's twitchy discomfort. The tightly wound Murray will twist your insides into knots, and his impassioned reading of his manuscript is so musical it borders on slam poetry. The 16-year-old Earhart more than holds his own, his character carefully testing his words to best impress his older friends (watch how he waffles when they ask if he writes poetry).

And all this in a play stacked with silences, pauses and half starts. Aside from occasional surges of language ("that was like a crazy head rush-slash-heart attack," Jasper gushes), the dialogue is elliptical and sparse. While some playwrights force characters to plow ahead with dialogue, Baker makes her characters wait. These empty spaces are remarkable—and also uncomfortable or tense or weird. Are they real? By play's end, that question no longer matters.

SEE IT: The Aliens is at CoHo Theater, 2257 NW Raleigh St., 235-1101. 7:30 pm Thursdays-Saturdays, 2 pm Sundays through May 4. $25.