As you're in the most dangerous hideout of murders, you hear someone walking towards you and go to hide, but before you could Nikolai grabs you and restrains you. You instinctively panic but try to get away, as you're being dragged through the halls, you hear a voice. It was Fyodor and Sigma talking about plans to kill Dazai

Nikolai: I GOT THE RAT THAT WAS LURKING AROUND!

Sigma: oh... You were right?

Fyodor: good job Nikolai, I'm proud of you...