"Tayna babushkinogo sunduka" - pochti nichego neizvestno, no do Romki i ego druzey — geroev povesti — doshli otdalennye sluhi. I teper' mal'chishkam predstoit raskryt' taynu zabroshennogo doma i sunduka, obnaruzhennogo na starom cherdake. Im pridetsya ne raz risknut' zhizn'yu: pobyvat' na dne morya, spryatat'sya v labirinte ot chudovishcha i srazit'sya s monstrami.
