Kf2?

@Josh Tutin why would it be a blunder? all of the pieces are safe, up there. I just don't see how to untangle the knots

@Ryan Duncan the idea is that, to get there the pawn is counted as having moved through the square where the capture happens, it's like the idea for when you want to castle and the squares where the king moves through shouldn't be targeted by the opponent

Kg7

@Josh Tutin @Christoph S. @Dave Petit I would argue that since Ng4 does the trick for white, black can under promote to a Knight and hope for a draw

@Josh Tutin I figured c4 is a nasty trap black can play to get his promoted knight moving, so that if white takes black's pawn, he won't be able to promote his