The tailed detective Richard is drawn into a new criminal intrigue: an attempt was made on the head doctor of the veterinary clinic, Grigory Voshchinsky - they tried to poison him by planting a bag of poison in a cup. The vet miraculously escaped death, but the criminal was not found, he is still at large! At first, the detective suspected Voshchinsky’s young wife Lina, but she turned out to have a cast-iron alibi. Richard accidentally discovers a clump of bright red cat hair at the crime scene and comes to the conclusion he feared most. Is this heartless crime the work of a feline? With a heavy heart, Richie outlines a circle of suspects: the cat Francoise, who helped Voschinsky at the clinic; the cat Athos, full of nobility; passion of Athos Jules; mystic cat Leviathan; overfed cat Prapor... But why did noble animals need to make an attempt on Voshchinsky’s life? Where could the unfortunate veterinarian cross the path of the cat?...