Mads "Crumb" Krumborg need a new bike so he can take part in an important race against a neighboring school. But it will be difficult to afford to buy a new printer, since the boy's father suddenly decides to terminate his job to invent a machine that according to him will change the world. At the same time a couple of crooks wind of his father's invention, and when the family Krum Borg's future is in problems, Crumb and his siblings to the occasion and save the day.

Everything is normal with the Krumborg family – but when you know them, nothing can surprise you anymore. The two robbers Boris and Ivan want to kidnap Krumme. Krumme wants to learn to ride a horse. Mom wants a healthy Christmas. Dad doesn't want a healthy Christmas. And it's hardly surprising that Krumme's Christmas present for Yrsa ends up under Mrs. Olsen's bed, or that caretaker Svendsen tries to repair Mrs. Olsen's sink – even though it's not broken. And the youngest member of the family, Grunk, has eaten all the Christmas decorations. Yes, everything is completely normal in the Krumborg family...

克拉姆是一个出生在非常普通的家庭之中的丹麦男孩。克拉姆的父亲（Laus Høybye
饰）是一名小学教师，而克拉姆就在父亲所执教的小学里念书。克拉姆的父亲饰学校里出了名的暴脾气，他认为自己的儿子理应给学校里的其他孩子树立良好的榜样，可是，卡拉姆叛逆的性格让他总是成为各种恶作剧的始作俑者，这令父亲感到非常的头疼。
克拉姆的妈妈想成为一名幼儿园老师，此时正在考取资格证，再加上家里一堆永远都做不完的家务和两个只会调皮捣蛋其他什么忙也帮不上的孩子，母亲的脾气难免会日益暴躁。虽然整天吵吵闹闹，但这就是幸福的一家人的日常。

Three children are accidentally transformed into fish after consuming a potion made by an eccentric scientist. The kids end up in the sea, with one problem: they must find and drink the antidote within 48 hours, or forever remain as fish.