“We can forgive the Arabs for killing our children. We cannot forgive them for forcing us to kill their children,” said Israeli Prime Minister Golda Meir. “There’s a weight a man can accrue,” William (Oscar Isaac) tells us in “The Card Counter.” “The weight created by his past actions. It is a weight which can never be removed.”

And yet, William may think for a moment that the weight can be lifted. We hope so, even as we learn about the unforgiving weight he bears in the latest from the master of the stories of tortured, lonely men, writer/director Paul Schrader, going back to his screenplay for “Taxi Driver.”

He says his name is William Tell, as in the old story about the archer ordered to shoot an apple balanced on the head of his son. As in the overture to “The Lone Ranger.” And as in the word “tell,” which can mean the narration of a story or, in the poker world William lives in, it can mean the inadvertent gesture that reveals more about the opponent’s hand than he or she wants you to know. We later learn that it is not the name on his birth certificate and prison record. So the choice of the name is significant, though it may be more related to the second meaning of the word than the first.

William says he was surprised to find that being confined to prison was more comfortable for him than he expected. He liked the routine. He liked the simplicity. And it was in prison that he learned the kind of concentration and focus that enabled his life after prison, as a highly skilled card player, blackjack and poker. Card counting is a difficult skill that can be learned and those who do it well can compensate for the odds that favor the house in blackjack. William goes from casino to casino, moving all the time and quitting each game early enough that his winnings do not attract anyone’s attention.

He does nothing else. He has so completely blocked out the normal distractions of life that he will not stay in the casinos. They are too filled with distractions and sensory overload. He stays in nondescript motel rooms. But he makes them even more generic, covering every lamp, every piece of furniture with white sheets, tied with twine. There is nothing in his life but the cards.

And then he meets two people. The first is La Linda (Tiffany Haddish in a beautifully understated but confident and layered performance). She is an intermediary between investors who stake top-level poker players as an investment, and she wants to add William to her “stable.” He is not interested.

That is, until he meets Cirk, pronounced Kirk (Tye Sheridan), a troubled young man who has a connection to the events that led to William’s prison sentence. William wants to help him, and that means playing poker in the high-end games La Linda can get him into.

Along the way, we learn about the disgraceful atrocities that Cirk’s father and William inflicted and the disgraceful injustice that had them bearing the responsibility while the instigators flourished. Schrader takes on an ambitious set of issues and understands the way to make it work is to give us believable, flawed but intriguing characters, with magnificent performances and stunning visuals. A scene where La Linda and Willam walk through an illuminated display is one of the most stunning of the year.

And can we just admit at last that Oscar Isaac is one of the finest actors in the world? He is mesmerizing here, the coiled control and the flashes of feeling, of longing, a simply gorgeous performance, one of the best of the year. This is a powerful film that fully earns its power.

Parents should know that this film includes some intense, disturbing and graphic violence, with torture of prisoners by US military, a prison fight, and murder, as well as very strong language, smoking, drinking, and sexual references and situations.

Family discussion: Why did William wrap the furniture? Why was it so important to him to help Cirk?

If you like this, try: “First Reformed” by the same writer/director