A king strangled by its own pieces
A knight delivers check; the king cannot move because every escape square is occupied by its own pieces. Nothing can block a knight check; knights jump over. The classic setup is a queen sacrifice that drags a defender onto the king's last flight square. Then the knight finishes.
Knight forks. Check the king, eye the rook on f8.
Go on then, take it.
3 more clean runs (at any point) to reach Recall.
Black king walled in by its own pieces. Knight and queen ready.
3 more clean runs (at any point) to reach Recall.