The twins had hardly noticed that Histoire had been missing for the past two hours. Tsuki was in Itsuki's room where she would most likely spend most of her time when she was not sleeping in her own room. Itsuki had been spending his time with Kirei, which explained her absence to Kuro. Tsuki apparently was not aware that her brother had been spending time with another woman. He had rarely taken interest in women and that interest would only be short lived considering that the person he was most interested in would be arriving the next evening.
She had not yet told them what was to happen because she appeared in the base in a quiet and dark room. The base was at its busiest in the later hours of the evening, meaning that it was hard to notice who was around and who wasn't. When Kuro appeared, a member approached him and began talking to him casually as though he had left the room only a few minutes ago or something similar.