Academician Donnikov, the creator of the “Health Reserve,” where stars and politicians are treated, died in a car accident, leaving his daughter Masha orphaned. And a month later a pigeon brings a strange letter to their chapel. In it, it says that the academician’s death was not an accident, but a murder—and Masha must find a reliable person to conduct a secret investigation. Masha turns to detective Alexey Kisanov. He doesn’t believe in the supernatural, considering the “pigeon letter” a cruel prank—but he still agrees to take the case out of sympathy for the girl. He is assisted by an assistant, Igor, whom Masha’s feelings evoke more than just simple sympathy… A conversation with the academician’s relatives unexpectedly lifts the curtain over the unseemly secrets of the “Health Reserve.” It seems that Donnikov became a victim of the intrigues of his high-ranking patients… The investigation takes a dangerous turn: now someone is trying to kill Masha. Who? Who needs the academician—and his daughter—to die?!