Santi would never have imagined that overhearing a suspicious conversation between two thieves would draw him—along with Olívia and Mateu—into an adventure that will take them all the way to Mallorca, to the imposing organ of Santanyí. There, a closely guarded secret lies hidden, but they are not the only ones searching for it.
Clumsy yet dangerous criminals, clues concealed in sheet music, hidden mechanisms, and a thrilling chase will push the Mistirius to test all their talent as detectives.