Originally posted by Mephisto2 Yes. For completeness, black's last move couldn't have been with the king either, because he would have been in double check (and especially by the pawn who couldn't have moved itself).
Originally posted by jatyap The correct answer wouldnt be g4-f6 because your king would be in check if the pawn takes the knight.
It should be:
1. g4-h6! gxh6 (or h2... doesn't matter)
Nope. If 1. Nh6 gxh6 then 2. Qd1+ isn't mate because of Kxg6.
The puzzle is in fact a retro puzzle and fetofs showed that 0. ... f7-f5 must have been the last move so gxf6 e.p (you read gxf6 as Nxf6 which it isn't, a lowercase first letter is pawn takes from the file indicated) is playable and mates in two.