This morality tale will leave you shaken

★★★5 Rated R. 116 minutes.

“The Killing of a Sacred Deer” is, as you might expect from the reunion of actor Colin Farrell and filmmaker Yorgos Lanthimos, Farrell’s director in “The Lobster,” a strange, wonderful, flawed — and deeply disturbing — thing.

Make that profoundly disturbing.

Compared with 2015 “Lobster,” a dreamlike, dystopian fable in which people who fail to find life partners by a certain age are transformed into animals, “The Killing of a Sacred Deer” is weirder and more unsettling, by another order of magnitude. As Farrell put it in a recent interview with Vulture, the new movie is “the nightmare that a character in ‘The Lobster’ may have. You’d wake up relieved to be in the world of ‘The Lobster’ if that was your dream.”

As he did in the earlier film, Lanthimos, working from a script written with frequent collaborator Efthymis Filippou, places Farrell’s character in a tight spot. Here, it’s no parallel universe, but one that looks and feels very much like the one we actually inhabit. It may not sound like reality — Lanthimos has a destabilizing habit of directing his actors to deliver their lines, however bizarre, with a flat, almost affectless cadence — but the universe of “Sacred Deer” is, in most other respects, an entirely ordinary one.

That is, until a 16-year-old boy named Martin (Barry Keoghan of “Dunkirk”) takes the sense of mild disequilibrium that the movie opens with and upends it like a table with a wobbly leg, throwing the placid life of Farrell’s Cincinnati heart surgeon, Steven Murphy, into chaos. Martin, the son of a former patient of Steven’s, is no ordinary teenager, and not just because of the insistent, vaguely creepy nature of his attachment to the cardiac specialist, who gives the boy attention — and expensive gifts — yet who also seems deeply uncomfortable in his presence.

There are times, early in the film, when the unhealthy intensity of Martin and Steven’s connection — not to mention the older man’s evasiveness around others when asked about the boy — implies a sexual history. Yet that is not the case. Rather, Martin’s clumsy attachment and stiffly formal behavior suggest that his character is not just on the autism spectrum, but well beyond it, as if the character existed in another dimension of social awkwardness and inappropriate comments.

Eventually, after Steven’s two children (Sunny Suljic and Raffey Cassidy) become mysteriously — and apparently incurably — ill, alarming Steven and his wife (Nicole Kidman), Martin delivers an ultimatum. While preposterous, it sets up the chessboard of the narrative in such a way that the characters, like pawns, can move only in prescribed, preordained ways, toward a horrific conclusion that is at once awful and inevitable.

Martin, who at this point seems part god and part demon, serves a role that is more allegorical than literal, in a story that gradually becomes a meditation — or, rather, a howling cry — on the impossibility of justice and atonement, and the tenacious grip of guilt. At one point, after Martin has bitten Steven — and then bitten himself to show parity — he says, “Do you understand? It’s a metaphor. It’s symbolic.”

It’s difficult to convey the simultaneously sickening and sobering effect of watching “The Killing of a Sacred Deer.” In his most bracing and maddening morality tale yet, Lanthimos doesn’t so much paint himself into a corner as he runs into it, headlong, dragging us with him all the way.