There are incredible things on the remote South Sea island of Titiwu: a school that you can skip with impunity and a harmony between humans and animals that was thought to be lost. The absent-minded Professor Habakuk Tibatong has taught some animals to speak. For example, the pig lady Wutz, the shoebill Shush, Ping Penguin and the monitor lizard Wawa. On the rocky reef, the elephant seal sings his "traurögön Lödör" all the time. Unfortunately, every one of them except Wutz has a speech impediment. The orphan Tim Tintenklecks helps the professor when it comes to getting the animals excited about a joint project. And one day it happens: a block of ice is stranded on the shore. Inside is an egg from which a primeval creature hatches - the Urmel. And it can even talk. Professor Tibatong, who has always believed in the existence of the Urmel, does something stupid...
The stubborn bighead Gerhard Jäger, sentenced by the murder commission, reluctantly postpones service according to the regulations of the water protection police. Does he hate water like the plague? Until his new colleague Arda Turan, a former high-performance swimmer, brings a breath of fresh air to the WaPo team with her lively nature and direct Ruhrpottschnauze. Police chief Frank van Dijk, a real sonny boy and passionate water rat, is also on board. He spends every free minute jet skiing and flirting, but at WaPo he holds the wheel firmly in his hand. And then there is Lena Preser, the secretary of the troupe, who always gets amazing insights from the bottom of the ground with her perseverance. Under the strict eye of ambitious boss Maria Kruppka, the investigative team solves the most exciting cases and repeatedly clashes with the arrogant crime chief commissioner Carsten Heinrich from the main department.