Main motif of this puzzle: Mayet's mate
In Mayet's mate, a rook checkmates the king. The rook is next to the king, but can't be captured, because it is protected by a bishop (or a queen on the diagonal), which does not guard any escape square.
Learn more in this guide.
The hint button is in beta test. We recommend to use the button only after you've thought about the puzzle for some time without finding any idea.
Read more about the hint button in this blog post.