Chess puzzle (Checkmate)
Moves: 1. e4 c5 2. Nf3 Nc6 3. c3 d5 4. exd5 Qxd5 5. Bb5 Bg4 6. Be2 Nf6 7. Na3 e6 8.
Nb5 O-O-O 9. Qa4 a6 10. c4 Qf5 11. Nc3 Bxf3 12. Bxf3 Ne5 13. Be2 Nd3+ 14. Bxd3
Rxd3 15. O-O Bd6 16. a3 Qh5 17. h3 Rxh3 18. gxh3 Qxh3 19. f4 Ng4 20. Rf2 Qg3+
21. Rg2 *
Position (FEN): 2k4r/1p3ppp/p2bp3/2p5/Q1P2Pn1/P1N3q1/1P1P2R1/R1B3K1 b - - 4 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 1013
Best move: Qe1#