Stealing a pet rat? “What nonsense!” - you will think and be very mistaken. After all, the girl whose pet disappeared is the niece of a US congressman, who only came to Russia for a short time. The kidnapping of a rat threatens an international scandal! Fortunately, Tosca, the faithful friend of the famous detective Felix Kuropyatkin, is studying at the school where the American delegation is located. Who, besides him, will be able to return the priceless rat in just two days?!