Chess puzzle (Checkmate)
Moves: 1. d4 Nf6 2. c4 Nc6 3. d5 Ne5 4. e3 e6 5. Qd4 d6 6. e4 g6 7. Bg5 Bg7 8. Nc3 h6
9. Bh4 O-O 10. Bg3 Nxd5 11. Bxe5 Bxe5 12. Qd3 Nxc3 13. bxc3 Qf6 14. Rc1 d5 15.
cxd5 exd5 16. exd5 Bf5 17. Qf3 Rfe8 18. Ne2 Qg5 19. g3 Qxc1+ 20. Nxc1 Bxc3+ 21.
Kd1 *
Position (FEN): r3r1k1/ppp2p2/6pp/3P1b2/8/2b2QP1/P4P1P/2NK1B1R b - - 1 21
Black to move.
Themes:  Middlegame Mate in 1 
Puzzle rating: 477
Best move: Re1#