Chess Problem

Here's an interesting problem from Nabokov. He composed this in April 1967 while in Italy. He was hunting butterflies, but failed to catch any. He thought this problem up instead.

This is White to move and mate in three. After White's correct move, there are two possible replies by Black, both leading to Mate in 3.

Enjoy!

I'm sure this will be easy for the non-Duffers!

Duffer is one of the great words in English! It's archaic and uncommon, but captures the idea so well.

In chess, I'm pretty much a duffer. In other things, not so much.