1 Kxe1 Qa1 2 h3! and White wins by promoting to a knight. The key is to
make sure the knight reaches c5 after removing the c4-pawn when the Black
queen is at a2; then ...Qa1 Nxb3 is mate. So 2 h4? is only a draw. Note
also that White must take off the c5-pawn before the c4-pawn, or else a
timely ...c4 throws off the parity.