Our current idea with the pieces arranged a little less obviously. Again a routine scan of the Black king’s lines reveals that the bishop on c5 is poised to be pinned, but you can’t pin a bishop along a diagonal; it can bite back. So once more White first performs an exchange, taking the bishop with RxB. After Black replies RxR, the bishop has been swapped out for a rook—a suitable target. Now White plays Ba3 and takes Black's rook a move later, winning a piece.