Originally posted by Mephisto2
You mean Nc6, I assume. And then ... ?
Oops, sorry, that's right. Nc6. And then...
1. Nc6! Kxc6 (if the king doesn't take the knight, both pawns are lost anyway through some combination of knight forks, x-rays and straight captures)
2. Bf6 Kd5
3. d3! a2 (if the king moves, he either gives up the d-pawn or gives up the a-pawn by x-ray)
4. c4! dxc3 (enpassant, if the king moves, well, you know what happens)
5. Bxc3 (covering the promotion square a1)
After that, the black king doesn't have much to do except get in the way of white's d-pawn, which will eventually promote.