Correct answer: Nd11...Nc2 2.Q:c2# 1...a2 2.Qb4# 1.Nd5?? zz 1...a2 2.Qc3# but 1...Nc2! 1.Nc4?? zz 1...a2 2.Qd3#/Qb2# but 1...Nc2! 1.Nd1! zz