Hello All, Doctor Z is ready to operate. My solution: variation #1 1. Rg4+ fxg4 2. Qg6+ Kh8 3. Qh7++ variation #2 1. -Kh8 2. Qxh6++ variation #3 1. -kh7 2. Qg6+ Kh8 3. Qg8++ variation #4 1. -Qg5 2. hxg5 fxg4 3. Qg6+ Kh8 4. Qh7++ Edward