There's an international crime wave of thefts of precious violins by Stradivarius. Rox must prevent another in the case of concert violist Petrovitsj, who is in the country for a concert. Xavier and Olivia go undercover as orchestra members, on kettledrums viz. with a gizmo so ROX can take over playing. They prevent a robbery attempt by a man wearing a venetian mask and Rick helps work out the logical suspect, while cheekily exploiting Josephine's idiotic belief in ghosts.
