Find the decisive blow (difficulty 1590)

12345678 hgfedcba

Black to move

Show solution
12345678 hgfedcba
  1. f7–e6 key move
  2. d7–e7
  3. e6–e7

What makes it

The king strikes, a queen given up, and the attack wins. The same move hits two or more targets at once, and nothing covers them all. 19 half-moves of forced play.