The company “Inseco” participated in a tender to supply equipment for the oil-extraction industry worth forty-seven million dollars and, according to all forecasts, was supposed to win. However, the tender was unexpectedly won by an unknown one-day firm: a few hours before the auction, its management offered more favorable terms. Inseco vice president Vadim Tregubov discovered that the competitors lowered their price by only two thousand dollars. This made him think that someone from the company’s closest circle had leaked the information about the tender amount included in the application. But who could it be? With this question, the businessman turned to the well-known detective Drongo…