在鼠洞里，小伙伴们欢声笑语，共享快乐时光，温暖彼此的心。避尘番外

　　7-year-old Bertil's parents are at work and Bertil are home alone and bored. He is the only child in the family since his sister Martha died of an illness. But everything changes when he meets little Nils Karlsson Pyssling and they become friends. Nisse who lives in the basement in a room he rents from the rat Tjofsan,wich is cruel.