The massive white stone door suddenly closed on its own.
This caused Shen Anmin, Zhang Xuezheng, and Xu Huifang and the others to be taken aback.
They immediately picked up the falling square metal piece, trying to press it back into the groove on the stone door.
However, the entire white stone door showed no response at all, which made Shen Anmin and Zhang Xuezheng even more anxious, as they had long since come to regard Tang Kexin as their own daughter.
Xu Huifang held the square metal from the groove in her hand for a moment, sensing that at this moment, these two pieces of metal were absorbing energy from the world around them on their own.
So, she speculated, "The opening of this stone door might require the energy within these two pieces of metal to support it."
