Kiri review: Sarah Lancashire gives a staggering performance in Jack Thorne’s think-piece on race, adoption and the press

• Meet the cast of Kiri
• National Treasure writer Jack Thorne considers making TV drama based on Grenfell Tower fire

Lancashire plays Miriam, the bright yet unorthodox social worker who signs off and oversees Kiri’s visit to her biological grandparents, during which the child disappears. Miriam finds herself, in her own words, “in quite a serious amount of s***”: in the eye of a brutal media storm and being blamed by the press, her employers and the police.

Miriam is a bohemian Bristolian woman who lost her young son to cancer and has an awful – yet cruelly humorous – relationship with her elderly mother. She doesn’t go anywhere without her flatulent and faithful hound, Jessie. Miriam’s tough, no-nonsense exterior encases a sensitive and bruised soul who Lancashire portrays with incredible nuance.

On the day of Kiri’s visit to her birth grandparents, every stakeholder is a ball of nerves. Highly-strung foster mother Alice, played convincingly by Lia Williams, is clearly reluctant to let Kiri go. Kiri herself has an anxiety-induced nosebleed. There’s fear and doubt in grandfather Tobi’s eyes as Miriam drives away. However, Miriam’s determination to believe she’s made the right decision means that she won’t accept the gravity of Kiri’s disappearance until she literally sees her body in the woods.

This moment of realisation is a beautiful piece of drama. All dialogue is drowned out by the woeful notes of a piano and we simply see a close-up of Miriam's face as it registers the tragedy and begins to buckle with sadness and disbelief.

Lancashire has some excellent lines, too. In a meeting where Miriam’s spineless employer brainlessly repeats that “99% of the time her judgement is usually impeccable”, she snaps. “You like that percentage, don't you? Stick a flake in it before you try and sell it to the tabloids, why don’t you?"

The media angle is integral in Kiri – just as it was in Thorne’s Bafta-winning series National Treasure. In the same meeting with Miriam’s employers, a point is raised that was made by the British press. “The papers are claiming that we prioritised her cultural needs over her safety needs. They’re claiming that we allowed her into an unsafe home in order to ‘tick our lefty boxes’.” Later, when Tobi goes to identify his granddaughter’s body, he sees the tabloid headlines about his son and begins to rip the papers off the shelves.

Kiri's race is also a huge factor in the story. This first becomes obvious when she is en route to her grandparents' house in the back of Miriam's car, and she says: "I'm black, I need to find out how black people live, I get it." It is raised again when Miriam is hounded by reporters and one shouts out: “Did you allow her unsupervised contact because she was black?”

It is after Miriam’s name is leaked to the press and she is suspended from work that she begins to spiral, and eventually ends up vomiting on her friend’s rug.

This series is already showing how difficult the decisions are that social workers make every day in the UK, posing questions about transracial adoption and making us think about the role of the British press – proving once again that Thorne is one of the most thought-provoking dramatists in the country.