Correct answer: Nf31...Ng5/Nh6/Nh8/Ne5/Nd6/Nd8 2.Rf2# 1.N1e2?? zz 1...Kf3 2.O-O# 1...Ng5/Nh6/Nh8/Ne5/Nd6/Nd8 2.Rf2# but 1