Figure[White to move]

Find the kernel of a discovery for White. This time it runs horizontally: White’s knight masks his queen’s path along the third rank. The point: your routine scan of the board needs to include attention to any friendly pieces on the same diagonal or rank or file as the knight. Here Black’s queen is loose, and White wins it with QxQ by first evacuating the knight from f3 with a check—i.e., Ng5+.