Chess puzzle (Checkmate)
Opening: Caro-Kann_Defense, Caro-Kann_Defense_Classical_Variation
Moves: 1. e4 c6 2. d4 d5 3. Nc3 dxe4 4. Nxe4 Bf5 5. Ng3 Bg6 6. h4 h5 7. Nf3 Nd7 8. c3
e6 9. Bf4 Ngf6 10. Be2 Be7 11. Qd2 Nd5 12. c4 Nxf4 13. Qxf4 Bb4+ 14. Nd2 Qa5
15. a3 Be7 16. O-O-O Bxa3 17. bxa3 *
Position (FEN): r3k2r/pp1n1pp1/2p1p1b1/q6p/2PP1Q1P/P5N1/3NBPP1/2KR3R b kq - 0 17
Black to move.
Themes: Queenside Attack Middlegame Mate in 1 
Puzzle rating: 669
Best move: Qxa3#