Snöänglar is set the night before Christmas Eve, while Sweden is paralysed by heavy snowstorms. Five-week-old baby Lukas inexplicably disappears from his home in a Stockholm suburb. The young parents are in shock. But seasoned police officer Alice believes that something is not quite right in their stories. She becomes obsessed with the case. Other people become suspicious of Lukas' mother Jenni who took sleeping pills that night and doesn't remember a thing, a nurse who had expressed concerns about the baby's safety and Jenni's own mother Kajsa.