They weren't entirely people anymore. You've heard of the manticores, haven't you? That's what they were. And the features they had in this memory -- it's exactly what Matine thought she saw on Schue, before.

She let them out and he tried to put her behind him. He started shooting; hit the first and the second, but the second one he hit in the throat instead of the head and it kept coming. A third came around from behind and he moved, but she... didn't. She smiled and it went for her. He kept shooting but he was running out of ammo so he went for the door. He couldn't get it open the first time but they were eating her, which I guess bought him some time.

He got the door open just in time for one of them to grab him in the back. He only had one bullet left and he knew he was dead, they were cutting off the exit, so... he shot himself.