Quote Originally Posted by CoccoBill View Post
But there's still

1. a7 Qd6
2. crap
2. Re1

I think 1. a7 is the way to go. What was problematic for me was figuring out what a7 does than Kg7 doesn't, and I found a line where a7 matters.

1. a7 Qxa8
2. Rxf4+ Qe4
3. a8=Q Qxf4
4. Qd5#

With that in mind, and with 2. Re1 looking like it does the job after 1... Qd6, I think this is the solution.