After a justly celebrated off-Broadway run at the Roundabout Theatre Company’s Laura Pels, Stephen Karam‘s knockout drama The Humans has moved to Broadway, courtesy of everywhere-these-days producer Scott Rudin. A smart decision was made to hold on to the exquisitely matched acting ensemble and also the play’s, well, human scale by re-mounting it in the Helen Hayes, the smallest Tony-eligible house. As a result, the play retains its remarkable power as a tale of sorrows veined with silver threads of humor — a kind of requiem for life in New York in the aftermath of the 9/11 terrorist attacks and Hurricane Sandy that makes a Big Statement by making no statement at all.

Set in a Chinatown basement duplex (the hyper-realistic set is by David Zinn), the long one-act begins as a young couple still moving in prepares Thanksgiving dinner. Brigid (Sarah Steele, Alan Cumming’s know-it-all daughter on The Good Wife) and Richard (Arian Moayed, Rock The Kasbah) seem, on first glance, to have lucked out: The digs look almost spacious. A spiral staircase joins the two floors, and there are arched entryways; Christmas lights twinkle. Look closer and you’ll note the laundry-list of compromises New Yorkers optimistically embrace in the search for living quarters: Exposed pipes hang from the ceiling; gray meter boxes jut out from the walls. To get mobile phone reception, you have to cantilever yourself into the frame of a window looking out onto a butt-strewn alley or, as Brigid cheerfully describes it, “the interior courtyard.” The windows themselves are barred and there’s no natural light to speak of, which is happy-making for waterbugs the size of rats that skitter across the bathroom floor.

Every few minutes a thunderous pounding can be heard, which Brigid attributes, not convincingly, to the clueless ancient woman who lives above them. Other basement noises intrude as well: the boiler switching off and on; the machines in the laundry room. Her parents Erik (Reed Birney) and Deirdre (Jane Houdyshell), who’ve driven in from Scranton with Erik’s dementia-addled mother Momo (Lauren Klein) to see the place, are none-too-convinced. It’s too close to the devastation of Hurricane Sandy and practically around the corner from the site of the Twin Towers.

Yes, Brigid and Rich feel lucky; she’s a struggling composer working two bar jobs to pay off her college debt; he’s working toward his master’s degree in social work, though he threatens to be a permanent student; a trust fund that won’t kick in till he turns 40 is looming in the not-too-distant future. That news pricks up Erik’s ears. He has labored at a private school for nearly three decades as a facilities manager, barely getting by; Brigid never lets more than a few minutes pass without reminding him that he’s never helped her out financially. Aimee is an emotional wreck, having just been dumped from the partner track at her law firm and her longtime girlfriend while contending with an ulcerated colon that will require surgery.

As I wrote back in the fall, sounds like fun, no? And yet for much of the play, these and other details are revealed with wise-cracking yet affectionate humor, at least until the kids begin to notice that Erik has been hitting the beer supply with unusual determination. As the evening moves like nature from light into darkness, Karam and The Humans: Sarah Steele & Reed Birneyhis incomparable director Joe Mantello (WickedOther Desert CitiesThe Last Ship) take this first-class ensemble and us interlopers along a journey that’s part family drama and thriller: Those brain-rattling crashes grow louder as the cutting jibes turn to panic from an unexpected place. The play’s growing darkness links the larger man-made and natural disasters to these unfolding personal tales, a prism refracting the white light of their terror into a spectrum ranging across the evil humans inflict upon ourselves to the forces of nature we cannot control.

Although the cast couldn’t be bettered (and the standout remains the wildly gifted Steele), I thought they were still settling into the rhythms of a larger performance at the critics’ preview I attended. Revelations that unfolded gracefully the first time around seemed to falter a bit and claim more of the spotlight, and I assume this will pass in very little time. I can only reiterate what I wrote earlier, that The Humans is tremendously exciting theater, and I remain convinced that you won’t see a better play this season.

Over at the Signature Theatre, those rubber-limbed, putty-faced clowns Bill Irwin and David Shiner are offering a welcome reprise of their tonic for the winter blues, Old Hats. Once avatars of the New Vaudeville, these two clowns have mellowed into welcome guests proffering their acts of mild astonishment (Irwin’s ability to extend his neck with E.T.-like wonder chief among them).

Old Hats: Bill Irwin, Shaina Taub & David ShinerThe big change is in the musical accompaniment. The original run of Old Hats featured songs and accompaniment by Nellie McKay, a brilliant musician of sui generic sensibility that worked as a foil to the silliness around her. Shaina Taub, an accomplished singer and songwriter, and her fine band, are more of a piece with Irwin and Shiner’s antics. Neither better nor worse but equally pleasurable and distinctly different.

Most of the routines will be familiar to those who have seen earlier iterations the show, whose highlights are some audience-participation shenanigans and the big finale, in which several folks are put into the service of filming a silent Western. The only thing assured is the sound of laughter.