Ostfrieslandkrimis

A school class follows their teacher into the mudflats and comes back without him. Was he an irresponsible person who put his class in great danger and died himself? Or did a few diabolical students take advantage of the situation to get rid of a hated teacher? Ann Kathrin Klaasen does not believe in it and initially lets the main suspect, the student Laura, run. Laura leads her directly to her friend Sascha, who posted a death notice from the teacher on the net just a week earlier. During the chase, Frank Weller falls from a scaffolding and suffers brain trauma.
When the teacher's body is recovered, Ann Kathrin is torn in her concern for Weller, her obligations to her son Eike, and the case, who takes a completely new turn with the appearance of BKA official Elisabeth Fädli. Because the body out of the mudflats is not the teacher, but a colleague from the BKA. Like Fädli and other colleagues, this was switched off for 24/7 monitoring of the highly relapsed sex offender Gerd Eichinger. The man is a ticking time bomb. Meanwhile, Laura and Sascha get the fleeting Eichinger, who has settled in with them in an aunt's holiday home on Norderney. The presence of the attractive Laura makes Eichinger wrestle with his inner demons.
When a stranger makes him an immoral offer that would allow him to flee abroad, the young people are in great danger. Ann Kathrin reverses the question, what really happened in the mudflats. She targets the BKA officials. Even if her boss Ubbo Heide disagrees, she is convinced that they know more than they admit and that they are the key, to find the youngsters.