Lucy poked her head out and made sure everyone had returned to their rooms before she quickly ran towards Susie's room, clutching a pillow.

Knock, knock, knock...

She gently knocked on the door and whispered, "Sister, open the door."

Grandma didn't allow her to sleep with her sister because she was afraid that she would keep her sister up at night by chatting, and both of them wouldn't be able to sleep well.