agb2002: The first idea that comes to mind is the maneuver 18.Bxh7 Kxh7 19.Rxd6 Qxd6 20.Ng5+ hxg5 (else loses the queen) 21.Ne4:A) 21... Qd5 22.Nxg5+
A.1) 22... Kh8 23.Qh3(4)#.
A.2) 22... Kh6
A.2.a) 23.Qh4+ Kg6 24.Qh7+ Kf6 25.Ne4+ Ke7 26.Bc5+ Kd8 (26... Ke8 27.Qxg8#) 27.Qxg8+ Kc7 28.Qh7 f5 and White loses material.
A.2.b) 23.f5 exf5 (due to Qh4# and Nxe6+ and mate next) 24.Nxe6+
A.2.b.i) 24... Kh7 25.Qh4+ Kg6 26.Nf4#.
A.2.b.ii) 24... Kh5 25.Qg5#.
A.2.b.iii) 24... f4 25.Nxf4 with the double threat Nxd5 and Qh4+.
A.2.b.iv) 24... g5 25.Qh4+ Kg6 26.Qxg5+ Kh7 27.Qh5#.
A.3) 22... Kg6 23.f5+
A.3.a) 23... exf5 24.Ne4+ Kh7 25.Qh4+ Kg6 26.Qg5+ Kh7 27.Qh5#.
A.3.b) 23... Kf6 24.fxe6+ looks winning (24... Ke7 25.Rxf7+).
A.3.c) 23... Kh5(6,7) 24.Qh3#.
B) 21... Qe7 22.Nxg5+
B.1) 22... Kh6 23.Qh4+ Kg6 24.Qh7+ Kf6 25.Ne4#.
B.2) 22... Kg6 23.f5+ exf5 24.Nf3+ Kh7 (24... Kf6 25.Bg5+ wins) 25.Qh3+ Kg6 26.Nh4+ Kf6 (26... Kh7 27.Nxf5+ Kg6 28.Nxe7+ Nxe7 29.Qxd7 wins) 27.Rxf5+ Ke6 (27... exf5 28.Qxf5#) 28.Qf3 looks winning (28... Qxh4 29.Qd5+ Ke7 30.Rxf7+ Ke(d)8 31.Qxd7#.
C) 21... Qb8(c7) 22.Nxg5+
C.1) 22... Kg6 23.Nf3+ Kf5 (23... Kf6 24.Qg5#; 23... Kh7 24.Qh4+ Kg6 25.Qg5+ Kh7 26.Qh5#) 24.Nh4+ and mate next.