Jozek unexpectedly is put to a harsh test when his mother, a seamstress by profession, succumbs to an unfortunate accident and is forced to lie in bed for several long months. The boy stays alone, has nothing to live on, and finally lands on the pavement. On the advice of a friend, he enters the "legion of the street", making him one of the many juvenile newspapers. It turns out that the boy's mother is waiting for a hard operation, and its costs can be covered only one way - the boy must be a "master", that is, he has to deliver newspapers. A bicycle is necessary for this. Meanwhile, the opportunity arises to get a bike - a street cycling race is organized, and the main prize is the bike. Józek decides to take off.