Everybody in the Andresen householder is puzzled by Kalle, who is not behaving at all like himself. He doesn't turn up at mealtimes, he seems distracted when anybody speaks to him, and he vanishes for long periods at a time - nobody knows where he goes!
Meanwhile Kostas is caught in a speed trap travelling at 112 km an hour in a 50 km zone. That will mean losing his driving licence for three months! Kostas is horrified. But then the police officer who has called round to see him makes a suggestion: if Kostas lets the Testing Station borrow his pickup for two days, for testing purposes, they’ll forget about the whole thing. Kostas is only too pleased to hand over his pickup, forgetting for a moment that there is 50 kg of feta cheese on the back. A couple of hours later he makes his way to the Testing Station to get the cheese back… only to discover that nobody knows anything about his pickup, the "officer" who dealt with him or any tests. Kostas has been conned. He immediately reports they matter to Pia down at the police station.
Together with Olli and Lorenz he now works out a cunning plan to trap the criminals who have stolen his truck - with the help of a tracking device and Lorenz’s private car.
Meanwhile, Stefan and Hanno decide that somebody should follow Kalle as well - but they lose him when he gets on a bus. So the next time they also employ a tracking device, with the help of which Stefan and Hanno trace Kalle to a car workshop, where Kalle appears to have found the love of his life: a huge dog called Belinda, a cross between a Labrador and a Bernese mountain dog. Funnily enough, Pia's team also turns up here – because this workshop is where the stolen cars end up, too. When Belinda’s master tries to get away from the police, Kalle is able to stop him at the very last moment... so he can turn his attention back to Belinda once more.