At the school where detective brothers Dima and Alyoshka studied, life went on as usual. And somehow I couldn’t believe that in this usual cheerful chaos a crime was being prepared... And it all started with the appearance of a new chemistry teacher at the school - the previous one, nicknamed It seems, Zhenya, was attacked by some hooligans, and he ended up in the hospital. The new chemist Volchkov immediately developed a vigorous activity: he set up a laboratory in the basement, where he showed all sorts of experiments, and organized a wrestling section. The boys immediately respected him. Everyone except Dima and Alyoshka. The experiments in the basement seemed somehow suspicious to them. It looks like Volchkov showed up at the school for a reason. Wasn’t he the one who took Zhenya out of the game to take his place? But why?..