It all began with a cat... Someone’s pet, left out on the street, turned the life of a young woman named Katerina upside down and set off a tangled investigation. Katerina is a talented and devoted veterinarian, ready to spend the night at the clinic for the sake of her animal patients. She sincerely worries about their fate, which is why the mysterious case of a sick cat leaves her anything but indifferent. The cause of this “illness” is poison. The only question is where it came from and who it was intended for: an animal or a human? Katerina manages to find out that the cat lived in an apartment with an elderly woman. Posing as a district doctor, Katya visits the building and meets a suspicious tenant named Vera. Meanwhile, the police are investigating the death of an elderly man who fell from a window, but most strangely, both he and his dog had also ingested poison. How are these two cases connected?
