Correct answer: Nd21...Ke7 2.Q:f7# 1...Kd5 2.B:f7# 1.Nc1?? zz 1...Ke7 2.Q:f7# but 1...Kd5! 1.Nc5+?? 1...Ke7 2.Q:f7# but 1...Kd5! 1.N