Skewer Advanced Puzzle (Rated 1316): Skewer — Win a Rook

A skewer is the mirror image of a pin: you attack a more valuable piece along a line, and when it steps aside, a piece behind it gets captured. In the chess endgame skewers are devastating, because material is scarce and every rook decides the game. Here Black slides a rook up the open e-file, checking the king while lining it up with the white rook behind it. The king must answer the check, and the moment it leaves the line, the exposed rook falls. One forcing sequence wins a full rook.