Chess puzzle (Checkmate)
Moves: 1. d4 e6 2. c4 b6 3. Nf3 Bb7 4. Nc3 g6 5. d5 Bg7 6. Bg5 Ne7 7. d6 cxd6 8. Qxd6
f6 9. Bh4 Nf5 10. Qf4 Nxh4 11. Qxh4 Nc6 12. e3 Qc7 13. Ne4 O-O-O 14. Nxf6 Nb4
15. Rd1 Bxf3 16. gxf3 Qe5 17. Ne4 Qxb2 18. Nd6+ Kb8 19. Qe4 Nc6 20. Rb1 Bc3+
21. Kd1 *
Position (FEN): 1k1r3r/p2p3p/1pnNp1p1/8/2P1Q3/2b1PP2/Pq3P1P/1R1K1B1R b - - 7 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 880
Best move: Qd2#