Het zakmes shows how deep children’s friendships can be. Mees and his friend Tim, both six years old, are in grade three. The day before Tim moves to Almere he shows Mees his new beautiful red pocket-knife in the schoolyard. Mees is even allowed to hold it for a moment. When the teacher, one of the strict old-fashioned kind who don’t like pocket-knives, comes close by, Mees quickly puts the knife in his pocket. Immediately the bell rings and the boys run inside. The lesson starts and they forget the pocket-knife. The next day Mees wants to give the knife back but Tim has just gone with the removals van and has not left his new address behind.