Denmark, 2016. A blurred note is found in a bottle that has traveled across the ocean for a long time. After deciphering the cryptic note, Department Q follow a sinister trail that leads them to investigate a case that occurred in 2008. At the same time, new tragic events take place that test their faith and deepest beliefs.

Four rogues, who were best friends as kids, have one big problem: they're sitting on both sides of the law. Martin is a policeman, while Nikolai, Ralf, and Timo can't distinguish between personal possessions and the possessions of others! When all four find themselves in a fix, they're forced to return to their former tricks against a common foe, Mr Niemeyer. Martin is not as successful, however, either at his job or marriage, and thinks he deserves a better life. Now he sees an opportunity to save his career by "playing" with his old friends on a mission that is so crazy that even the two foolish brothers can do some good.

Sensitive 12-year-old Alf is the low man on his class' totem pole, and he's sick of it. Forming a secret, Machiavellian alliance with another student who also has grown weary of being bullied, he hatches a plan to throw a wrench into the well-oiled gears of the school social order. Everything seems to go according to plan, until Alf discovers that turning the tables on his tormentors has its own dire consequences.