Just one day before his tenth anniversary as a schoolteacher Arend Vogel is all stressed out and can't take it any more. He takes refuge at the Familie Knots' comic book swap shop where he finds most of the family members still acting like big children.

Pietertje, the boy from next door is having trouble at home and is taking it out on other people's possessions, such as Cousin Herbert's brand new and expensive kite and Hansje's bicycle tyres.

Tante Til is ecstatic to have a little girl as a house guest but Grandpa is very annoyed and nervous when he hears the news. The girl in question, Trudy turns out to be a little brat who is angry because her parents are off having fun while she is send to a weird family she doesn't even know.

The new neighbor from number 25, Ms Pronk, is being annoyingly nosy. She also tends to copy other people's way of dress and even tries her hand at painting art just like Tante Til.

The entire Knots family has to cut down on expenses because Tante Til hasn't sold a single artwork in a while. On top of that Neef Herbert breaks Tante Til's antique vase she was planning to sell. Hansje is instructed to lure a lot of customers into the comic shop. Lucky for her, a wealthy little boy gets stuck between the elastic ropes Neef Herbert was playing with outside.

Meester Vogel is suffering from nightmares and confides in Grandma. She tells him all about the Knots family secret and more importantly, to ask Hansje out on a date. Cousin Herbert has found a set of Indian clothes and weapons to play with. The toy gun and bow and arrow are quickly confiscated by Onkel X, who always wanted to have a weapon of his own.

The entire Knots household is upset about one thing or the other. Grandpa hurts his knee while re-enacting his marriage proposal in front of Oma, so a doctor is send for. Soon the medic, Dr. Heman, begins to charm all the women in the household. Neef Herbert has got a present for Onkel X and Tante Til's 21st wedding anniversary. Tante Til is uncomfortable being reminded that their marriage has remains childless. Hansje is upset because Arend has moved out of his lodging without telling her.