Jitka, an untrained 16-year-old hairdresser, runs away from the youth home and returns to a group of hooligans led by a young man named Vilda. They all hang out in Prague's arcades and make their money by petty theft and fraud. One day Jitka takes a liking to Tonek, a waiter's apprentice. The girl returns his feelings, but at the same time she doesn't want to drag him down. But her cronies have no scruples. And so Tonek becomes a member of their gang.