Most films we view emotionally and cerebrally but Son Of Saul, the holocaust drama from first-time director Laszlo Nemes, is experienced physically: it hits like a truck, leaving bruises under your skin; it pulverizes like a wrecking ball, smashing the core of your being into broken pieces. Although I saw it months ago at a festival, where I watched and recovered from dozens of other films, writing this review has been like peeling back a bandage over an old wound, revealing an aging and soiled disfigurement that hasn’t healed.

The film’s subject matter, the inner workings of Auschwitz-Birkenau as told from the perspective of a Sonderkommando named Saul, is inherently harrowing. It’s Nemes’ depiction, though, of the stoic efficiency, the mundane horrors, and the mechanical labor that make it groundbreaking and devastating.

The Sonderkommando were prisoners in the concentration camps who were forced to do the grimiest and most repulsive jobs — disposing the bodies, cleaning blood-stained floor tiles, and collecting the victims’ belongings — but were given basic amenities like food and beds. For these men, remorse and grief left long ago, a general numbing that ignores the pain remains: carrying corpses becomes like moving supplies, shoveling ashes feels like moving sand.

In order to evoke this perception and avoid exploiting the subject matter for cheap thrills like a horror film, the cinematography by Mátyás Erdély leaves all of the atrocities out of focus, off-screen or at the edges of the claustrophobic frame (the film is projected in the narrow academy ratio). There is no time to look and even less to mourn. Our gaze is instead directed towards Saul as he works, scrubbing, shoveling, carrying — except his trade is the disposal of the dead who are forgotten as fast as they burn. Nemes’ style is a slow social realism that recreates banal mass murder, where human experiments on children don’t raise eyebrows, where any sense of human empathy have been insidiously stolen.

The opening sequence before the title card, which might be the film’s most brutally effective moment, traces a group of Jews that are escorted by Saul and the other Sonderkommandos into the camp where they are stripped to their bare-skin and forced into the gas chambers. As soon as the door is sealed, not an instance is wasted; the Sonderkommandos immediately grab the victims’ belongings, collecting it for the camp’s officers.

In another film, we might stop, enter into the chamber with those being killed, or have a character stop to contemplate the murder wistfully. Son Of Saul is a film too unrelenting for such sentimentality; it is a step beyond eliciting tears. It takes place after the ducts in the characters’ eyes have dried up, when the only thing left to do is raise productivity, to kill as many in the least amount of time as possible.

But amidst the horror, genocide, and hatred is a conflict of Saul’s attempt to find dignity, altruism, and humanity. Although most of the film is plotless, tracing our protagonist’s everyday existence in the camp, a plot emerges when he discovers a corpse of a boy that may have been his son. He risks his life to give him a proper Jewish burial. The film is bleak and unrelenting, but proves itself not pointless or pornographic. It is about a man’s search to find meaning or humanity in a nihilistic and nefarious environment.

Despite the formal virtuosity, the compelling acting, and the unique perspective on the inner workings of a concentration camp, many might wonder what the worth in watching such horrific images is. We know what happened but we haven’t come close to feeling it. Here is an important film precisely because it is impossible to forget: close your eyes, hear the aching shrieks, and walk out of the theatre; the overwhelming images will lurk behind. It still hurts. The wound will never heal.