It’s going to be fun for student biologists during practical work! This isn’t sitting there brooding over test tubes. The students of Professor Svetin were merrily splashing and frolicking in the river Chulymka, celebrating the first day of field trials. And suddenly, from the opposite bank, shooting started… at the guys stunned with fear. By some miracle the boys managed to escape—only one was hit. But Professor Markov was far less lucky: they found him with his head shot through. Beside the body, the rifle was left—one that Svetin’s son had discovered an hour earlier. Understanding that his father had been cynically set up, the son turns to professional bodyguard and detective in one person—Yevgeniya Okhotnikova. Especially since the list of victims is growing, and the children of the unjustly accused professor are at the top…