I've said this before about mysteries by Karin Fossum: They are good to read but hard to write about. So much of the story is inside the heads of the characters, in how they think about their actions and the consequences of those actions (in the case of the perpetrators) or in how they reason out the solution of the crime (in the case of the detectives).
Black Seconds is about a child disappearance, but it isn't typical. There are no evil serial killers, only a few troubled young men and some bad decisions.
Like an earlier Fossum book I read, Don't Look Back, it's set in rural/suburban Norway, among typical Norwegian characters, such as oil workers, housewives and students. This is worth mentioning, I think, because so many Scandinavian writers are focusing these days on issues of immigration and urban crime. If you are looking for that angle, Fossum won't provide it. Instead you will get a restrained and measured analysis of a series of events and their aftermath.
Trust me, this is good, even though it sounds like not so much.