There has been a burglary at Falkenstein Castle! To make things worse, the unknown thief not only stole precious paintings but also Count Falko's beloved collection of monocles. Meanwhile, the Martinshof ranch experiences hard times due to the lack of holiday guests. Only the chaotic Schmüll family arrives with their misbehaving children who threaten to turn the ranch upside down. Luckily, Bibi and Tina will not stand idly by. The two friends begin their search for the mysterious burglar while also working on a plan to save the ranch from bankruptcy.