C270 We're being watched

That afternoon, went to the Extermination to attend lessons for the first time.

He went straight to the 17th floor, but there was no one on the 17th floor. He was startled and did not make a call. He went up to the 18th floor.

However, there was no one on the 18th floor. Since the start of the school, he had been busy with his sister's matters