The life of Top and Cop, dogs of amateur detectives, is full of adventures. They, together with Inspector Fox, are engaged in catching a fairground thief. Then they go on vacation on the icebreaker Lastochka with Captain Buk to admire the northern sowing. Where they are faced with the mystery of an encrypted pattern on a sweater, which indicates the location of hidden treasures. They also host their cousins, Bessie and Lassie, who want to persuade the brothers to find and move into the house of their childhood dreams. After which they unwittingly find themselves drawn into events related to the investigation of a new detective case involving stolen securities from a match factory in which criminal gangs are involved.