Le Club des Cinq et le coffre aux merveilles

The Five spend the summer at the Trois-Pignons farm. They soon discover that it is built on the ruins of a castle. But the soil of Francville holds an even greater secret... An antique dealer tells them that, although nothing remains of the castle today, many mysteries are still hidden in the old cellars. They need to find the secret passage that leads to the entrance of the underground tunnels!