The Riddle of the Silver Snake

Since Agatha was accepted into the Guild of Gatekeepers, a secret organization unraveling the most complex crimes in London, the girl dreamed of a real case. And finally, she got the chance to prove to everyone that she is an excellent detective. A rather strange event occurred at the National Gallery: one of the curators has gone missing. There is every reason to believe that he was kidnapped. But why would someone attack a staff member of the museum? And what do the world's most famous paintings have to do with it? Agatha has no idea what astonishing discoveries await her!