The main special effect in A Ghost Story is older than the movies: After a young Dallas musician (Casey Affleck) dies in a car crash, he returns as a ghost to the home he shared with his wife (Rooney Mara), and he’s draped in a sheet with hastily made cutout eyeholes, like some misbegotten Halloween costume.

Yet writer-director David Lowery channels the absurdity of this setup into an extraordinary mood piece that amounts to his best movie yet. Lowery has quickly developed a filmography that mines for awe in solitude, and here delivers a cosmic variation on that theme, exploring the ineffable relationship between people and the meaning they give to the places that have value in their lives. Both formally ambitious and emotionally accessible, A Ghost Story transforms its main stunt into a savvy dose of minimalism with existential possibilities that cut deep.

The appeal of A Ghost Story is all the more impressive in the wake of Pete’s Dragon, a movie Lowery made on an unfathomably larger scale and designed for mainstream appeal. But even as A Ghost Story exists in a niche, it’s not preaching to the converted; Lowery manages to find entertainment value and genuine intrigue from his outlandish scenario, synthesizing the magical realism of his earlier films with a tighter grasp of tone. The result is a soul-searching drama in which powerful revelations emerge less from a satisfying destination than from the beautiful struggle involved in getting there.