
Solution

1… Rb4 skewers the white queen to the bishop on f4.
Since black already attacks the bishop once (with his queen), white won’t be able to defend it sufficiently.
ie. 1… Rb4 2. Qe3 Rxf4 (and black queen defends the rook).
1… Rb4 skewers the white queen to the bishop on f4.
Since black already attacks the bishop once (with his queen), white won’t be able to defend it sufficiently.
ie. 1… Rb4 2. Qe3 Rxf4 (and black queen defends the rook).