The Secret of the Running Shadow

Here comes September first! Back to school again! Dasha and Petya have a new classmate - Olya Zhukova. And Stas has lost the most beautiful classmate. What happened? Did she really run away from home or was she kidnapped for ransom? Who are these villains? The suspicious new neighbors of Petya? Or is the mafia behind this? Dasha and her friends, risking their own lives, will have to start their investigation…