C1997 What a Coincidence?

"How is it?" Zhang Ya asked Wan Xingke, "How often does this stone door close?"

"Fifteen minutes. " Wan Xingke said,, "Chang Ning and I will follow your instructions and open it every time. "

"Yes. " Zhang Ya nodded. This was similar to her speculation.

"Is it dangerous inside?" Wan Xingke asked.

"A little. " Zhang Ya nodded and said, "But fortunately, everyone came back safe and sound