Correct answer: Nb31...g5 2.B:f5# 1.Nd3?? (2.Nf4#) 1...g5 2.B:f5# 1...Nc5 2.N:c5# but 1...Nd4! 1.Ne2?? (2.Nf4#) 1...g5 2.B:f5# 1...Nd4 2.N