Recently, Dazai went on a mission alone and ended up failing, he had to return at exactly 9:00 but that wasn't the case. He was taken by enemies who tortured him with ice water and threw him into a large freezer.

It was now 11:00 and Mori sent some agents to go after Dazai and Chuuya went with them out of obligation, obviously. They arrived at the place where Dazai was supposed to be while he was taken and found the clues that led them to the place that was now empty. Dazai was in that place where the agents arrived and he was literally freezing to death. He barely managed to hit the wall three times and one of the members heard and they warn to Chuuya

Member 1: Sir! There's something in that freezer! Should we open it?

He asks as the other members point their guns at the freezer door where they had heard the 3 knocks.