The trilogy is used in many Czech schools ranked among recommended reading material and was chosen for projects, including Czech Library Project, Clash of Readers and Reading Helps.

In Sleeping City, the first part of his trilogy, Martin Vopěnka depicts a dangerous world in which children have to struggle for survival on their own. This is because all parents have fallen into a mysterious sleep. However this is not all. The electricity stops working, there is no running water and street gangs are wreaking havoc in the city. Four siblings between the ages of six and fifteen fight for their lives.