White to play and mate in 3. Find the key move.

How should White continue after 1...Qg7? Now the e5 square is guarded twice, hence the threat won't work.

But isn't the queen simply hanging on c2? What if Black captures 2...Rxc2? White to play.

Black defends e5 with 1...Qh8. So this time there would be no 2.Nxg7. How should White continue?

But what happens if it's simply taken with 2...Rxc8? White to play.

Finally, what happens after 1...Re2? How should White continue?

Black captures on c5 - this is forced as the threat was Nxe7#. It's White to play, what happens now?