Far away, past the moon, floats Bol Nul. On that planet lives Blitz, a green space man. He lives completely alone there and he does not mind at all, until a bird lands on its planet. Blitz and the little bird Tjilp become friends, but after a while Tjilp wants to return to earth. This makes Blitz realize how lonely he is. He builds a rocket and flies to earth in search of a friend who looks like him. But is there someone on earth like Blitz?
Since 2013 eight books about Blitz have been published, of which De bol met de klok is the most recent. The newest will be the anniversary edition and will be released summer 2023.