The 4 ½ friends consist of three boys, one girl, and a dog. Kale, the founder and leader of the detective agency 'Kale and Co.', along with the twin brothers Steffi and Karsten, Friedel, and their dog, Pentamorph, get involved in various adventures as they attempt to solve mysteries and strange cases.

What happened at school that has all the children upset? The commotion is due to a mysterious break-in at the teachers' office! The strange aspect of the case is the items the thief chose to take with him: two jars of raspberry jam, a teacup, a timer, two books, and a makeup bag.

The only eyewitness is Friedel from the group of 4 ½ friends. And the most absurd detail? The man Friedel saw sneaking into the school during the break-in looks very much like the school principal. Is it possible that the principal is the main suspect in the case? The 4 ½ friends are once again faced with an exciting mystery. Will they be able to solve it?