A similar idea. Black has the familiar kernel of a discovery on the long diagonal leading toward White’s king. First the king needs to be drawn onto the diagonal; here as in the last position, the queen can be sacrificed to force the needed result: Qh1+, requiring KxQ. Now the rook’s job again is to both unmask a check and add to the pressure on White’s king. This it does with RxN++, putting the king in double check and so requiring it to move. Its only flight square is g1. Now Black goes in for the kill with Rh1#. The bishop protects the rook and also cuts off the king’s flight square to the north—a classic mating pattern we considered in the chapter on discoveries by the bishop.