D.S. Ellie Miller

Ellie Miller is a small-town detective sergeant expecting a promotion when a boy's murder brings in outside detective Alec Hardy instead, forcing her to work the case under him rather than lead it. She's warm, chatty, deeply embedded in the community, and utterly unprepared for how close to home the investigation will cut.

Colman plays ordinariness with total conviction, so the wear the case puts on Ellie lands like a physical blow. The writing trusts her decency as the show's moral compass, and Colman never softens it into sentimentality; her grief and fury feel lived-in, and she anchors a bleak story in real human warmth.