All the discomforts of home

Deep in the second act of “Heartless,” the murky new play by Sam Shepard, a luminous lunacy lights up the stage. It is generated by Lois Smith and Jenny Bacon, playing a mother and daughter who thus far haven’t had much to say to each other and wouldn’t even appear to have much in common, aside from that inconvenient matter of being related. But just listen to them now.

They’re hitting lines to each other with the hyped-up, exhilarated precision of Olympic Ping-Pong competitors. And what are they talking about? Dream vacation spots (Mom favors “the wilds of Borneo”), how you’d get there, which of them is in more pain and what kind of pain it is — you know, the usual family banter.

To an outsider this conversation might sound crazy. But as Ms. Smith and Ms. Bacon render it, the talk has that irritated, in-sync patter you associate with old vaudeville teams — and the private languages of families. These characters may have mixed feelings about each other, to put it mildly, and they sure as hell aren’t happy.

But they’re having the time of their lives riffing like this. So, I might add, are the actresses playing them. And if only for a few delighted moments, you feel you’ve come back to Shepard country, where there’s no place stranger — or more familiar — than home.

As much as any American playwright, Mr. Shepard understands that every family is insane in its own special way. With masterworks like “Buried Child,” “Curse of the Starving Class” and “True West,” this Pulitzer Prize-winning dramatist has secured his place in the hall of fame for portraits of domestic dementia.

“Heartless,” which opened on Monday night at the Pershing Square Signature Center, provides only flashes of the glorious theatrical glee and anguish that animate those plays. Directed with lots of air-devouring pauses by Daniel Aukin, with a stark black set designed by Eugene Lee, this Signature Theater production calls ponderous attention to its great metaphysical themes. And its symbols stand out like road signs on those lonely stretches of highway that Mr. Shepard so loves to write about.

But for Shepard aficionados, “Heartless” offers a fascinating focus on a figure that this restlessly imaginative author — in contrast to other great American playwrights, like Tennessee Williams and Eugene O’Neill — usually doesn’t pay much attention to: good old long-suffering, child-shaping, hearth-keeping Mom. And because Mom is played by Ms. Smith, even non-Shepard aficionados may want to see what this fine, eternally fearless actress is up to.

The world of Mr. Shepard is usually a boys’ town, a place where combative fathers, sons and brothers go head-to-head. “Buried Child,” “The Late Henry Moss” and “The Tooth of Crime” are all essentially Oedipal tales, infused with a poisonous paternal legacy and lots of testosterone. Even the battle of the sexes in “Fool for Love,” between possibly incestuous bedmates, takes place in the shadow of a father’s manipulative specter.

So it’s refreshing to find Mr. Shepard’s usual gender ratio reversed in “Heartless.” Of its five cast members, only one is male. That’s Roscoe (played by Gary Cole), a 65-year-old academic who has recently split with his wife of many years and is trying to make his way through an unmapped new world. These days, apparently, 65 is not too late for a midlife crisis. (Mr. Shepard, for the record, is 68.)

Having taken up with the much younger Sally (Julianne Nicholson), Roscoe winds up in a household of women. High on a hill, with views of the ocean and what is referred to as “the abyss” of Los Angeles, this home is ruled by Mable (Ms. Smith), Sally’s paralyzed mother, and her handmaidens: the dour Lucy (Ms. Bacon), Sally’s sister, and Mable’s beautiful, mute nurse, Elizabeth (Betty Gilpin).

Relations among these women are hardly relaxed, nor are they what they seem on the surface. The production has planted big, glaring clues to tantalize us, like those long, angry scars running down a couple of chests and stomachs. (If you want a hint as to what this might signify — at least in literal terms — you need look no further than the play’s punning title.)

Needless to say, Roscoe does not find much comfort, let alone his lost self, within this female crew. It takes Mable — wrapped up like a, er, mummy in her wheelchair — no time at all to diagnose his condition. “Rootless,” she says triumphantly, in tones to which Ms. Smith lends the finality of a death sentence.

Well, of course he’s rootless, and a vagabond and a homeless wretch and, most choicely, “spawn of the Air Force” (he was a military brat), which Mable also calls him. Homelessness is the primary existential condition in Mr. Shepard’s universe, even when you’re at home. As for any secure sense of identity, forget about it. Shadows and substance blur confusingly, and personal histories seem to change on a whim.

Mr. Shepard has said all this before, and with more dramatic urgency and clarity. Using an abstract set for “Heartless” was a mistake, I think. It divorces metaphor from life and isolates characters from one another. They seem to exist here mostly in relation to their symbolic status. (I found myself thinking of Christopher Durang’s priceless parody of mixed identities, Shepard-style, “A Stye of the Eye.”)

Ms. Nicholson and Mr. Cole work in an earnest, naturalistic vein that, perversely, makes their characters feel less credible. Ms. Gilpin does a good silent scream and generally makes the best of a part that isn’t really there.

But as the miserable Lucy, who dips freely into Mom’s medicines, Ms. Bacon cuts loose to delightful effect. In the second act, in particular, she gets high on her character’s bewildered resentment and on Mr. Shepard’s language, and so by proxy do we.

While Mable never leaves her wheelchair, that doesn’t mean that Ms. Smith is a static presence. On the contrary, as a true mother should, she endows this play with what genuine life force it has, her face ablaze with a Gorgon’s mythic power. A dauntless veteran of Broadway, Hollywood and the venturesome Steppenwolf Theater troupe, Ms. Smith has been given this play’s big, classic Shepard monologue, in which Mable remembers trying to relate to an oversize image of James Dean on a drive-in movie screen in the Wisconsin woods.

The soliloquy verges on over-the-top excess (heights Mr. Shepard never shies from), but Ms. Smith pulls it off, giving rapt, visceral immediacy to the tug of war between self and illusion at the core of all Shepard plays. Mable may have been paralyzed by time, circumstance and psychosis, but Ms. Smith and Mr. Shepard still have the muscles to heft a playwright’s poetry of loneliness into the heavens.

By the way, that movie that Mable is looking at? It’s “East of Eden,” in which a young actress named Lois Smith made her debut 60-some years ago.