White to move - mate in 3

Heinrich Wagner vs Alfred Binckmann, Bremen, 1927

[FEN "6k1/2b3r1/8/6pR/2p3N1/2PbP1PP/1PB2R1K/2r5 w - - 1 0 KQkq - 0 1"] [NAVIGATION "0"] [CUSTOM_MOVE "1"] 1.Nh6+ Kh8 2.Nf7+ Kg8 3.Rh8#