This is what generational trauma looks like. This impactful, multistranded documentary weaves together a dogged investigation into the horrific crimes perpetrated against generations of Indigenous children at a residential school run by the Catholic church in Canada, with accounts of the trickle-down of damage, from grandparents to parents to children. It’s a remarkably courageous and exposed work, particularly for co-director Julian Brave NoiseCat and his father, Ed Archie NoiseCat, whose painful journey together in search of healing is the film’s spine. The sickening facts of the case are presented with a respectful restraint but it’s impossible to watch this and not feel a cold, hard rage on behalf of the victims.

• In UK and Irish cinemas