Her comings and goings were so natural to the Professor that he was unaware that she was leaving the room until John Derringham broke off in the middle of a sentence, to rise and open the door for her.
"Good-by," she said.

"Aunt Roberta is not very well to-day, so I must not be late.

Good night, Cheiron"-- and she went out and closed the door.
"But it is quite dark!" exclaimed John Derringham.

"Is there a servant waiting?
She can't go all alone!" The Professor leaned back in his chair.
"Don't disturb yourself," he said.

"Halcyone is accustomed to the twilight.