Lesson
White to move. Main line: 1. Qxf7+ Rxf7 2. Re8#
Qxf7+ is a forcing sacrifice, not a speculative attack. The queen captures the pawn beside the king and checks from f7. The bishop on c4 protects the queen, so the king cannot capture it; Black’s rook is the only piece that can remove the check.
After ...Rxf7, the rook has been deflected from f8. Re8# then reaches the back rank: the white rook controls e8, f8, g8 and h8, while Black’s own pawns on g7 and h7 close the remaining escape squares.
The calculation is short because every move is a check. When an enemy rook is both a defender and the only possible recapturing piece, look for a sacrifice that forces it away from the rank or file it must guard.