Helpmate in 3 by G Paros 1933 Il Problema

Reproduced from the early collection of helpmates "Conspiracy" by Alain White, one of his Christmas series books.

This three-move helpmate shows great strategy culminating in a model mate. Every move is thematic. The Black queen prepares to flight-block her King, and has to take the scenic route e2, g4. There is a departure effect right on move 1, as The White King arrives on d5, a square formerly in check. Note moreover that the White knight is now pinned. On the next black move, Black arrives on g4. It is now time for the White king to perform a anticipatory unpin of the white knight. He goes to Kc4. Why does the white king not go to e6, the other available square? Because that is reserved for the mating piece. On Black's last move, the Black King arrives on f4 for his model mate. This horizontally unpins the White Knight, a nice effect. Se6 is a beautiful model mate. The whole thing works like a Swiss watch. The order of the moves is forced, and there is harmonious interaction between the white and black moves, and nice economy.