Tintin has set on another adventure in the country of Syldavia. This time Tintin, Captain Haddock, the Thompsons and Snowy fly to Syldavia to meet Professor Calculus on Lake Pollishoff, an artificial lake that has a curse on it. The trip is doomed from the start when Tintin & Co. barely survive a plane crash only to be saved by two Syldavian kids, Niko and Nushka. The crew meets Professor Calculus on the Villa Sproj on the lakeside but mysterious things happen when the group gets attacked by a frogman who is trying to steal an invention by Professor Calculus. Also in the story is Bianca Castifiore, her pianist Wagner and the ruthless Rastapopoulos.