Queens Gambit Declined Marshall Defense Fork Puzzle (Rated 886): Win a Fork — Crushing Middlegame Tactics

This classical chess puzzle comes from the Queen's Gambit Declined and shows a crushing middlegame tactic based on a fork and king safety. White’s last move creates a loose piece situation, but Black can exploit the exposed king and the vulnerable queen-side pieces. The key idea is to use forcing moves that check the king while simultaneously attacking another major target, turning a tactical refutation into decisive material gain.