Try: 1. Qxb4? waiting
1. ... Qf4 [a] 2. Qxf4 [A] #
1. ... Qe4 [b] 2. Qxe4 [B] #
1. ... Qd4 [c] 2. Qxd4 [C] #
1. ... Qc4 [d] 2. Qxc4 [D] #
1. ... Qxb4+ 2. R3xb4#
1. ... g2 2. Rh3#
But 1. ... f5!
Try: 1. R3xb4? [2. Rxh5#]
1. ... f5 2. Qd8#
1. ... Qf4 [a] 2. Rxf4 [E] #
1. ... Qe4 [b] 2. Rxe4 [F] #
1. ... Qd4 [c] 2. Rxd4 [G] #
1. ... Qc4 [d] 2. Rxc4 [H] #
1. ... Qxb4+ 2. Qxb4, Rxb4#
But 1. ... g2!
Solution: 1. R5xb4! waiting
1. ... f5 2. Qd8#
1. ... Qf4 [a] 2. Rxf4 [E] #
1. ... Qe4 [b] 2. Rxe4 [F] #
1. ... Qd4 [c] 2. Rxd4 [G] #
1. ... Qc4 [d] 2. Rxc4 [H] #
1. ... Qxb4+ 2. Rxb4#
1. ... g2 2. Rh3#