By the standards of the traditional ghost story, "A Ghost Story" isn't much of one. By the standards of the moody art-house meditation on love, loss, memory, forgetting, attachment, letting go and the nature of eternity, it's pretty darn great.

Okay, perhaps not great. But bold and strange, in that indie way. Poetic without being pretentious, and at times deadpan funny, this ballad of a lonely poltergeist is certainly not for everyone, but it is for some. Have I mentioned that it's shot in a squarish aspect ratio, with rounded corners, and bathed in the soft glow of nostalgia, like a Hipstamatic photo? Don't let that put you off.

Casey Affleck, playing a music composer identified only as C in press materials, is supposed to be dead for much of the film, hiding under what amounts to a white sheet — or something closer to a banquet tablecloth in size, given the way it trails him like a wedding gown — with two eye holes. After a bit of Terrence Malickian prologue, in which we're shown a collage of seemingly random, fragmentary snippets from C's life with his significant other, M (Rooney Mara), he dies, rather suddenly, in a car accident that — although it occurs entirely off camera — manages to be mildly shocking and entirely expected.

From that moment on, in this fable written and directed by David Lowery of "Pete's Dragon" and "Ain't Them Bodies Saints," C haunts M with the persistence of a dog who is waiting for his absent mistress. Or, rather, he haunts the old house that they lived in together. Standing around rather morosely — if a guy in a sheet can be said to be morose, and not, more accurately, motionless — C's ghost watches M devour an entire pie that has been left for her, as condolence food, by their real estate agent (Liz Cardenas Franke), and then he watches her vomit it all up. He watches her move on, bringing another man (Barlow Jacobs) home, and then he watches her move out.

He watches and watches and watches, as other, newer residents of the house come and go, even engaging in a little harmless poltergeist activity to spice things up. Part of the time is spent silently communing with the female ghost next door, whom C spots through the window. They stare at each other — soul to soul — speaking, in a way, through wry subtitles. (According to the credits, she's played by singer Kesha Sebert, who formerly stylized her stage name as Ke$ha. Because she is always under a sheet, you must take that on faith.)

There is very little spoken dialogue. Most of the words in the film occur during a house party, mutely witnessed by C's spirit, as a guest expounds, with the philosophical certitude of the man who is about to have one beer too many, on the impermanence of art.

Is that the point of the film? It's never quite clear. More important: Can a ghost "die" and come back to haunt itself? Lowery pushes the tropes of the haunted house film past the breaking point, creating something that is entirely original — and oddly, if not profoundly unsettling. Maybe that guy at the party is right. Maybe art doesn't last forever. But for a little while — long after the closing credits anyway — "A Ghost Story" manages to stick with you.

R. At area theaters. Contains some disturbing images and brief coarse language. 93 minutes.