Learn How to Spot a Mate in 2: Intermezzo Pin
This chess endgame-style tactical puzzle is really a forcing middlegame combination built around a pin and a check that leaves the enemy king with no escape. The key idea is to use an intermezzo check to drag the king into a worse square, then finish with a bishop-and-queen mating net. Even though White is materially ahead, the exposed king and trapped rook make defense impossible once the forcing sequence begins.