This image tells the tale. Ian's facial expression depicts discomfort, disappointment, and tiredness after realizing that the terrible blunder he just played gave him no way to avoid defeat in Game 12.
Ian had been impressing everyone, playing engine moves at an incredible speed with stunning precision. The game was fully in his hands. Sesse and all the engines were screaming victory for Black.
Ding opened with 1.d4, choosing a relatively calm line. But after a few moves, both players were out of their books, and the game got wild in no time. Both Kings were exposed, and Ian pressed on the King's side with a powerful attack. Liren tried to defend, but Ian's precision was astounding. Move 25 was a double exclam and gave Nepo a winning position:
This is a dream position for Black. After White 26.a4, Ian played 26...b4, and Ding took the pawn with the Queen, leaving the winning move there, at Ian's disposal:
Nf3 and game over. But here, Ian started to falter. He played the much inferior 27...Rag8, equalizing the game.
From there, Ian and Liren started playing another game. Blunder after blunder, in a rollercoaster rarely seen at this level.
At move 34, the final mistake: Ian collapsed playing the unbelievable f5??
Ding took the pawn in e6 with the rook almost immediately, and the game was over at that point.
Ian looked distraught, and his body language was, probably for the first time in this match, very straightforward: it showed desperation.
Now the two Candidates are tied, 6.0 to 6.0, with two games to go. Tomorrow Nepomniachtchi plays with the White pieces, and Ian will have to use all his mental strength to overcome today's defeat.
Here is the game:
And here is the press conference from the FIDE Official YouTube Channel:
Tomorrow Game 13, at 5 AM EDT, 11:00 CET, and 9:00 UTC.