Two targets, one move
A double attack (捉双) hits two pieces at once, and the defender can only save one. The horse is the natural fork artist — but look at the board: your horse on b8 is itself attacked by the chariot on f8 along the eighth rank. Running away is honest but slow; the winning shape is a fork that includes the king, because the check must be answered first and the second victim is left standing in the wind. Find the jump that hits king and chariot in a single move.