Richard Madden puts his intense stare to good use on the Netflix series “Bodyguard.” (Netflix)

A show hailed as England’s most popular BBC drama since “Downton Abbey” is now on Netflix.

“Bodyguard,” which drew 11 million viewers for its September finale in the U.K., is about cop and security specialist David Budd (Richard Madden, who portrayed Robb Stark on “Game of Thrones”). In the first of six episodes, which all dropped Oct. 24, Budd and his two kids are on a train to London. They’re asleep but he’s on high alert, wondering why a train security officer looks so worried.

Budd delves into the situation and learns there’s an alert about a suicide bomber — and that a seemingly suspicious man (because of his “Asian” ethnicity) went into a train restroom and hasn’t come out.

But then the man emerges and seems harmless. So we’ve judged him unfairly because of his national origins, it appears. Budd checks out the W.C. just in case — and finds the man’s wife, clad in a suicide bomb vest, her finger an inch from the detonator.

The negotiations between Budd and the distressed potential bomber are taut and terrifying — he not only wants to keep her from pressing the button but to keep security forces from shooting her. To better protect her, he wraps his arms around her and they pirouette in a dance of near death.

Budd proves to be a sensitive negotiator but is a personal wreck. An Afghan war vet with a scarred torso, he is scarred inside as well, suffering from PTSD, separated from his wife and drinking too much on lonely nights.

He’s promoted after his train experience to be “police protection officer” for haughty Home Secretary Julia Montague (Keeley Hawes). He hates her warmongering, yet there may be sparks between them, perhaps because of the adorable way he addresses her as “mum” — his pronunciation of “ma’am.”

Why watch a show that’s even tenser than our tense times? Because it’s brilliantly done, with superbly restrained acting and an irresistibly suspenseful plot, pivoting around the age-old questions of who can you trust — and what twists will happen next? But I do think a warning might be in order for wrung-out viewers: After watching, tune into “Mister Rogers’ Neighborhood” to calm down and carry on.