All he wants is for them to apologize.
The police learn about the crime like everyone else, through Snapchat. The video shows a terrified victim asking for forgiveness. When they find the body, it is marked with the number 2.

Inspector Huldar is involved in the investigation, in which he seeks the assistance of child psychologist Freyja as they will have to interrogate the victim's teenage friends.
They soon discover that the murdered young Stella was not the angel everyone said she was. Even so, who could have hated her enough to kill her?

Then another teenage girl disappears and more related videos come to light. When the body marked with the number 3 is found, Huldar and Freyja agree on two points:
A. that the truth is not at all simple.
B. that the killer has not finished his work.

And is there perhaps a body out there marked with the number 1 that they have yet to find?