The sanatorium security guard was strangled. A pharmacist was thrown out of a window. A scientist was shot. Before that, all of them received envelopes with numbers 1, 2, 3… from a mysterious killer. The envelope numbered 4 went to a wealthy businessman. Apparently, he’s next. And there are other envelopes too.
What connects these people is one thing: they are all childhood friends. So the motives for the murders should be found in their past? That’s the first thing that comes to mind for Drongo. But an experienced detective knows from experience that solving a crime rarely lies on the surface. You have to dig deeper. And search for what the criminal tried to hide from plain sight…