Strange goings-on are afoot in Tartu once more. Many of the city’s women have been robbed of their expensive designer handbags. When Mari’s Mum is forced to surrender her own favourite bag to the expert cycling thief, the old secret club decides to reunite to put things right once more. What at first seems a simple task becomes more complicated and more dangerous than the previous incidents that Mari, Satu, Reelika, Olav and Anton have dealt with. Can the children in the secret club really come out on top this time?