Yuki's Stormy Pin: a pin puzzle

Black to move. Find the one move that wins. About 1250 ELO.

From a real ChessLvl game against Yuki Tanaka (LVL 1). Black to move: one move wins.

Hint

Line up an attack through one piece to a more valuable one behind it.

What is a pin?

An attack through one piece to a more valuable piece behind it, so the front piece can't move.

How to spot it

Look along files and diagonals that run through an enemy piece to their king or queen.

Tip

A pinned piece can't move without exposing what's behind it. Attack it again and it usually falls.

Solve it on the board above, or take a hint. Every ChessLvl puzzle is checked by a chess engine to have exactly one best move.