Land Of Black Gold is the fifteenth volume in the series, Adventures of Tintin. The book was redrawn to be set in the fictional state of Khemed.
In the Land Of Black Gold, Tintin is puzzled by spontaneously exploding car engines all around the country. A little investigation reveals that this is because the petrol used in the cars has been tampered with in a way that causes explosions. This results in most vehicles reducing their use of gasoline, leading to economic crisis that threatens to bring war. As the country prepares itself for war, Captain Haddock is summoned and commanded to set sail.