Mysterious happenings are afoot at Marlinspike Hall as Professor Calculus heads for Geneva and then dissapears. Fearing he may be in danger, Tintin and Captain Haddock follow his trail as the plor thickens further.
Spies and secret agents try to prevent Tintin from rescuing his friend, can he succed with the help of the world famous opera singer Bianca Castafiore and some clever disguises?