1.Kh2 threat 2.Kg3 threat 3.Qf4
1...d2 2.Bd5 threat 3.Qxe4; 2...Qc2 3.Bc4; 2...Qxd5 3.Rxd5
1...e2 2.Sd5 threat 3.Qf4; 2...Qc1 3.Sc3; 2...Qxd5 3.Rxd5
1...Bxf6 2.Qg3+ Kxf5 3.Sd6
The pawn defences eliminate a potential check from c2, allowing White to unpin the queen, which each time has a new, unsuccessful defence which fails to a shut-off mate. The by-play variation makes good use of the pin.