In a small town in Wales, a group of teens sneak onto a building site while their families participate in a festive walk – only for tragedy to strike.

In the aftermath of the accident, the police investigation picks up steam. Polly becomes a lightning rod for the community's anger.

The inquest finally begins, and the community comes face-to-face with the corporation. Harriet makes a decision that has devastating consequences.

After a year of nearly bankrupting themselves, the families finally see their private prosecution in court – but will they get justice?