Set Play:

 1. ... e6/e5 2. Qxf8#

Try: 1. Qb8? waiting

 1. ... Sa8/e8/e6 [a] /b5 [a]  2. Qe5 [A] #

 1. ... e6/e5 2. Qxf8#

 But 1. ... Bh6!

Try: 1. Qxf8? [2. Qxe7#]

 1. ... Kd6 2. Qxe7#

 But 1. ... Sb5 [a] !

Try: 1. Kxc7? waiting

 1. ... e6/e5 2. Qxf8#

 1. ... a5 2. Qxa5#

 But 1. ... Bg7!

Solution: 1. Qd8! [2. Qd4#]

 1. ... Bg7 2. Qxe7#

 1. ... Se6 [a] /b5 [a] /d5 2. Q(x)d5 [B] #

 1. ... e5 2. Qxf8#