Books in the Tintin yn Gymraeg : Tintin in Welsh series

Tintin travels to the small kingdom of Syldavia where he is witness to a conspiracy against the young king, Muskar XII. The plotters plan to steal the ancient Sceptre of King Ottokar, symbol of the new king''s right to rule. Should the plot succeed, the king will lose his crown ? can Tintin help him before it''s too late? A Welsh translation...