22...Re2

Black lands another powerful blow, bringing the Rook to its seventh rank. The Rook can't be taken with 23.Bxe2 because of 23...Nxe2+, forking the King and Queen.

The Rook move 22...Re2 has one drawback. Black's own first rank is left vulnerable to back rank mates, but White is nowhere near getting a major piece into a threatening position.

Next move: 23.Nd2