This unscripted Adolescence moment is one of the show's most subtly frightening details

There was one particularly chilling moment in Netflix's Adolescence that sent shivers down many spines - and you might be surprised to find out it was improvised.

One of the most talked about shows of the year so far, Adolescence deserves all the attention it's getting. It really is the 'wake-up call' we can all learn lessons from and essential viewing in the current climate of increasing violence against women.

Filmed in one take, the one shot sequence adds to the frenetic and almost claustrophobic tension building up on screen. While many viewers wonder whether the show is based on a true story, we're all marvelling at the gripping performances - particularly that of Owen Cooper, who portrays 13-year-old Jamie Miller.

Some of the most haunting moments in the series play out in the third episode, between Jamie and Erin Doherty's clinical psychologist, Briony. One blink-and-you'll-miss-it detail was improvised and not even in the original script.

Because the series was filmed in one take, the cast rehearsed each episode until the lines and choreography were perfect before filming began. Each episode was filmed several times until the director deemed a take perfect enough to make the final cut.

Recounting how a yawn he was unable to stifle was expertly incorporated into the scene by Erin, Owen said on The One Show, "A yawn came to me and Erin did an amazing line."

Thinking on her feet to prevent the yawn from derailing the scene, Erin asked, "Am I boring you?"

"That took me back and it made me smile because it was unexpected and wasn't in the script at all," Owen explained.

It was that smile that conveyed everything that made Jamie terrifying - unreadable with a hint of twisted arrogance that could either imply guilt or simply a frightened young boy.

Young and inexperienced actor, Owen, detailed how he and Erin 'bounced off' each other as they deviated from the script during filming.

Erin Doherty also praised the talents of her breakout co-star, telling Hollywood Reporter, "Owen as an actor, he could have been doing it for 50 years and no one would have known any different. He just has the ability to go to these places and allow himself to just free fall in the moment. Honestly, some actors dream about achieving that."

She also opened up on how easy it was to appear frightened of Owen's character, as she found Jamie genuinely terrifying. She explains that outside of her character, she's personally very emotional and outwardly expressive - as Briony, she had to keep that contained.

Erin said, "The minute that he left the room, I got to breathe. It felt like some level of suffocation had left the room. It was just this emotional vomit, in a way."