Adolescence director ensured Katie was 'present' in every episode - the haunting detail you probably missed

There is a subtle and haunting detail throughout Netflix's Adolescence that weaves the character of Katie into the entire series, so that she is never far from the audience's thoughts.

The harrowing four-part drama has gripped the nation since its release, with the tale of 13-year-old schoolboy, Jamie, stabbing his classmate to death sparking vital conversations and providing a 'wake-up call' we must all learn lessons from.

The one-shot masterpiece features countless intricate details, from the unscripted moment that's one of the most frightening in the show, to how the director made sure Jamie's victim Katie's presence is felt in every episode.

Katie, played by Emilia Holliday, is seen a handful of times in Adolescence. Images of her flash onto the screen during the title sequences, her photographs are there again in various scenes and she is barely visible in the glimpse of footage of Jamie's attack.

Director, Philip Barantini, ensured that Katie's impact wasn't lost in the story of what unfolds for Jamie after the murder, though. Emilia can be heard singing throughout Adolesence's entirety.

“The voice in the score is Katie’s voice,” Philip told Tudum. “Katie is a part of the whole series. Her presence is always there."

Katie's voice rings out again during the choir rendition of Sting's Fragile at the end of episode two. Emilia's vocals play over the devastating last seconds that show Jamie's dad, played by Stephen Graham, laying flowers at the scene of his son's crime.

"There's a beautiful song at the end and Phil had this wonderful idea from the very beginning," Stephen told Netflix.

"He said what he wanted to do was have a choir and the voice of young kids singing this particular song that he had in his head from the get-go, actually."

The Boiling Point actor continued, "The beautiful process of it is, is that we used the choir from the actual school, and the kids from that area. The girl singing this is the girl who played the girl that got killed."