"W-what... did you do?"
Both the students and the school staff were running with all their might to somehow get farther from this chaos and hell. They didn't have the time to hear what Nurse Mitha said to Renir nor think how they were all freed at the same time. Their faces just looked at the school buildings that they thought could protect them from the chaos and these monsters creating chaos.
When Renir heard Nurse Mitha's question, he was not surprised as he did not have the intention to hide it from her. She already had her suspicion on him since before. He will eventually share this with her in secret if possible.
He stood up and before he answered, all of them heard a shout louder than what they heard from the Captain earlier;
"EVERYONE, ESCAPE THROUGH THE FRONT GATE. GET AWAY FROM HERE. FAST!"
Remember back on chapter 98 when Sceke mentioned he was tired because he recruited one of the leaders from the City of Misfortune?