Correct answer: Qg81...Kf3 2.O-O# 1...Nh4/Nh8/Nf4/Nf8/Ne5/Ne7 2.Q:g3# 1...f6/f5 2.Q:b7# 1.Q:g6?? (2.Q:g3#/Qe4#) 1...f5 2.Q:g3# but 1...f:g6!