Sam Shepard's latest play is a hazy look at another crazy American family

“I’d like to gaze out into the abyss for a while,” declares a wacko wheelchair-bound mother in “Heartless.”

Although watching Sam Shepard’s hazy new meditation on life and death and what’s in-between isn’t abysmal, it does become tedious.

But it also occasionally surges with offbeat humor. That’s not nothing, but not enough to make for a satisfying night.

As is the custom of the esteemed playwright of the Pulitzer Prize-winning “Buried Child” and “A Lie of the Mind,” an American family in all its grotesque inglory forms the focus.

And that word “focus” is used loosely, since Shepard isn’t a linear writer. In a home in the hills high above Los Angeles, 30-ish Sally (Julianne Nicholson) has returned. She’s in the process of documenting her life.

And what a life. For about 20 years she’s had a dead girl’s heart beating inside her. Undressed, she bears a long, angry scar, as fresh and bright pink as a newly butterflied roast.

She’s brought a guest — Roscoe (Gary Cole), whom she met on a talk show. An expert on Latin-American authors, he’s up and left his wife and kids.

Also on hand are Sally’s tightly wound sister, Lucy (Jenny Bacon), and their disabled mother, Mable (Lois Smith), plus Elizabeth (Betty Gilpin), Mable’s mute caretaker who wears Nurse Ratched drag, from sensible shoes to crisp hat.

Will anyone fly from this cuckoo’s nest? Is Elizabeth a figment of an addled mind? These and other questions emerge and are left unanswered over the play’s nearly two hours. There’s lots of talk (and singing) about living and dying, mentions of thick blue smog, an unseen barking dog, bloody feet and chatter of escape.

Odd? You bet. Shepard’s theater has its own rhythms and music — underscored by Eugene Lee’s abstract set. Director Daniel Aukin’s cast is all over the map — tinny and flat to too declamatory.

At their best, mysteries in Shepard plays pull us in. And even one great compelling performance can grab and hold us tight. As is, “Heartless” lacks all that; it just drifts — like smog.