Chess puzzle (Checkmate)
Moves: 1. e4 e6 2. d4 d5 3. Nc3 c5 4. exd5 exd5 5. Bb5+ Nc6 6. Nf3 a6 7. Bxc6+ bxc6 8.
O-O Nf6 9. Re1+ Be6 10. Bg5 Be7 11. dxc5 Bxc5 12. Nd4 Bxd4 13. Qxd4 O-O 14. Na4
Re8 15. b3 h6 16. Bh4 Bf5 17. Rxe8+ Qxe8 18. Bxf6 gxf6 19. Qxf6 Bxc2 20. Qxh6
Qe5 21. Qxc6 *
Position (FEN): r5k1/5p2/p1Q5/3pq3/N7/1P6/P1b2PPP/R5K1 b - - 0 21
Black to move.
Themes: Hanging Piece Endgame Back Rank Mate, Mate in 1 
Puzzle rating: 1003
Best move: Qxa1#