He remembered that whenever Wu Dayi approached the stone staff they had yet to collect, he would get a headache. He had also inexplicably developed a headache when they first entered this cave.
Putting the pieces together, He Dazhi suddenly understood. The thing that had been giving Wu Dayi headaches all along was that stone staff—not Quhu, as Luo Yunji had guessed!
As they were leaving, Little Fatty was still thinking about the cave full of jewels. He went to find Yanshe Snake, wanting to ask it to keep an eye on them and make sure nobody else snatched them away.
"You're leaving!" Yanshe Snake coiled around a stone pillar, lowered its head, and looked at Luo Yunji with reluctance.
"Mm! I know you haven't killed anything, so you're a good bug. We have to go now. You take good care of yourself, too."
"Thank you for saving me."
"Didn't you already help us find a treasure? We like it very much. Oh, and you should go out less from now on! If we could find you, other people could, too!" Luo Yunji kindly advised.
"But I have to go out and find food for my eggs!" Yanshe Snake replied, clearly troubled.
"Eggs can eat, too?" Luo Yunji asked curiously, tilting his head up to look at Yanshe Snake.
Yanshe Snake said nothing. Instead, it slowly lowered its head and let Little Fatty climb on. Then it carried him to the top of the stone pillar where it dwelled. There was a basin-sized stone trough there, filled with a transparent green liquid. Two white eggs rested in the liquid, each as big as both of Luo Yunji's fists.
"What's this water?" Luo Yunji asked curiously.
"It's the juice of spirit herbs. It'll help my eggs hatch safely and stay healthy."