Volume 1 of the Inkblotters series. The children in class 3a often have wild adventures, but in the end, they always stick together. After all, they are the Inkblotters - the class with the best ideas in the world. During the reading night at school, everyone is cozy in their sleeping bags when Jana-Ina claims that her white rubber tiger has been stolen. A thief in the class - Ben and Mia can't let that slide. And so begins a nighttime and adventurous search through the secret passages of the school.