Jo Idstad is thirteen. Jo is a good student at school, but he is convinced that life is dangerous. In order to survive at school, he has to avoid deadly dangers at all costs which, according to him include his roughneck classmates, life-threatening sports and pretty girls. He’d much rather stick to his preferred activities – such as solving mathematical equations and swapping football cards. These are the tricks that help Jo keep his life under control. But then one day, a new girl, Mari, joins his class – and nothing is the same again.
Not only is Mari a serious football player and second best in the class when it comes to maths – she’s also very cute. Before long, Jo realises that Mari is the girl of his dreams. But he will have to take some risks if he wants to impress a girl like Mari. All at once, things begin to go awry and it’s not long before Jo is in such hot water that he fears he may never see his fourteenth birthday. Jo’s last hope is the football card that the boys have been pursuing all summer long. The Liverpool goalie card could just save his life – if such a card exists.