In The Darkness

Eva is walking by the river with her seven-year-old daughter when they catch sight of a man's body in the water. Eva tells her daughter to wait while she calls the police, but when she reaches the phone box she doesn't call them. Instead she phones her father, and makes no mention of her discovery.
When the body is eventually found, it soon becomes clear to Inspector Sejer and his team that this was no accidental drowning - the man was the victim of a very violant killer. But the trail has gone cold. Until, one night, Eva receives a phone call...