Has the detective's beloved dog Tida really been kidnapped by criminals?! After all, the shepherd disappeared on the very day and hour when the apartment of a rich elderly lady was robbed. Accident? But the dog disappeared not far from the crime scene. Yes, there are a lot of coincidences... What should Tid and his friends do? The guys decide to look for the dog themselves - and at the same time for the robbers. It’s impossible to get on the trail, but one day friends find a very ordinary medicine box...

The story was also published under the title “The Secret of the Green Snake.”