Correct answer: Re41...K:e7 2.Q:e2# 1...Bf8 2.e:f8Q# 1.Nd8?? zz 1...Bf8 2.e:f8Q# but 1...K:e7! 1.Na5?? zz 1...Bf8 2.e:f8Q# but 1...K:e7!