I only wanted something quick to watch. One episode, perhaps two, before calling it a night. But within minutes of Stephen Graham appearing on screen as the terrifying Jurek Walter, that innocent plan had completely disappeared.

There are television villains who frighten you with violence, others who intimidate through sheer physical presence. Then there is Walter, a man who barely needs to raise his voice to make your blood run cold.

In Apple’s psychological thriller Nocturne, Graham delivers the kind of performance that makes looking away feel almost impossible. Every whisper, every calculated pause, every unsettling smile suggests something deeply disturbing beneath the surface.

And the most frightening thing? Walter doesn’t even need to leave his prison cell to destroy someone’s life.

A SERIAL KILLER WHO DOESN’T NEED FREEDOM TO CONTROL PEOPLE

For three years, Jurek Walter has been imprisoned in solitary confinement beneath Riverside Psychiatric Hospital.

His isolation is extraordinary. Staff members are strictly forbidden from revealing personal information because Walter possesses an almost supernatural ability to manipulate people through their deepest vulnerabilities.

The opening sequence establishes his terrifying influence.

Speaking through a sinkhole connecting his cell to another inmate, Walter calmly persuades the prisoner to fatally injure themselves against a wall.

There is no dramatic confrontation or elaborate escape attempt. Just a voice, a conversation, and a horrifying demonstration of psychological control.

It is an opening that immediately establishes the series’ most disturbing premise: sometimes the most dangerous weapon is the human mind.

STEPHEN GRAHAM MAKES EVIL DISTURBINGLY HUMAN

What separates Graham’s performance from conventional portrayals of serial killers is his refusal to make Walter a predictable monster.

He is softly spoken, almost motionless, and occasionally disarms people with a strangely childish giggle.

There are moments when he appears vulnerable, even sympathetic.

But those glimpses of humanity become another source of unease. Is Walter genuinely expressing emotion, or is he carefully constructing another psychological trap?

Graham makes that uncertainty utterly compelling.

Rather than relying on exaggerated menace, he allows tiny changes in expression to suggest entire conversations happening beneath Walter’s composed exterior.

It is a masterclass in controlled, understated acting.

A MISSING GIRL AND A TERRIFYING RACE AGAINST TIME

The story intensifies when Michael Frost, a teenager missing for three years alongside his sister, unexpectedly reappears.

His sister remains missing.

Investigators fear that her disappearance is connected to Walter, whose previous victims were buried alive and abandoned to die slowly.

Retired detective Jonah Lynn, played by Liev Schreiber, must confront the killer he imprisoned years earlier.

Joining him are FBI agent Alexandra Quinn, portrayed by Poorna Jagannathan, and undercover specialist Saga, played by Zazie Beetz.

Their mission is desperate: extract information from Walter before another life is lost.

But Walter understands something his visitors may be dangerously underestimating.

They need him far more than he needs them.

THE REAL HORROR IS WHAT HAPPENS INSIDE YOUR HEAD

What makes Nocturne so compelling is its willingness to trust the audience.

Information emerges gradually. Conversations carry hidden meanings. Apparently insignificant details become increasingly unsettling as the investigation progresses.

The supporting cast brings urgency and emotional weight, particularly through Jonah’s unresolved trauma and Saga’s dangerous involvement.

Yet Graham remains the gravitational centre of every scene.

Even when Walter is absent, his influence hangs over the investigation like an approaching storm.

The early episodes may contain occasional narrative gaps, but the psychological tension and extraordinary central performance make them remarkably easy to overlook.