Kb7, Qf8, Bf6, Nc8, pawn a6.
Mate in 3 moves, Novotny Chess.
Author: P. Zmilo, Bulgaria.
1Qh8^. Necessary move in the intersection point "h8" of Black queen and bishop. 1...Qg8+^. Again a necessary move. 2Qg7+^ Qf7^. Now when the theme is completed, white is free to play 3Bd5#.