In this collection of problems, Raymond Smullyan transports the game of chess to the world of the Arabian knights. The White King is Haroun Al Rashid, the White Bishop is his Grand Vizier, Archie. They are out to counter the Black King Kazir's attempts at invisibility, and to unmask the disguised Queen Medea. In addition, using the deductive logic that is the hallmark of these exercises in retrograde analysis, Haroun and Archie discover pawns who've robbed the royal treasury, lazy knights who refuse to move more than once or twice, and buried castles, as well as encountering any number of phantoms, genii, magicians, philosophers, and hermits.