Not the best photo, sorry.
It's hard to believe this block starts with 10" squares. Sew around the outside then cut diagonally twice. You end up with 4 HST that you use to make a large pinwheel block. Then cut that block equally into thirds both vertically and horizontally. You have 9 sections. Next step is to spin the outside blocks to make a churn dash with a little pinwheel in the center. This was so clever. I had done the Disappearing 9-Patch before but this is even more fun.