Here's a position in game 6 of the world championship. In the longest game ever in a world championship, Magnus Carlson played move 133. e6! Why can't his opponent just take the rook?

ANSWER: Because after 133. Qxf5 134. Ng7+ Ke7 Nxf5

After 8 games the defending world champion Magnus Carlson of Norway leads challenger Ian Nepomniachtchi of Russia by a score of 5 to 3 with 6 games to go.