The book tells the story of Ali Baba, a poor woodcutter who discovers the secret of a thieves' den, which can be opened by the magical phrase "Open Sesame." After taking some of the treasure, Ali Baba's life changes, but his secret is discovered by his greedy brother, Cassim, who meets a tragic end. Ali Baba, with the help of his clever slave-girl Morgiana, outwits the thieves and secures the treasure for himself. The story is a thrilling adventure that explores themes of honesty, intelligence, and the consequences of greed.