The Castle Conundrum

Set in the picturesque south of France, Frank and Joe Hardy embark on a mission to renovate a deserted town into a refuge for children. However, the project is threatened by rumors of a haunted castle and a hidden treasure of diamonds. As they encounter eerie phenomena and sabotage attempts, the brothers team up with French twins who aim to protect the castle from developers. With each clue leading to a dead end, the Hardys must navigate a web of mystery and danger to uncover the truth behind the ghostly legend and their adversary.