Tomb Raiding: Sign-In Begins in Golmud

I transmigrated into the fringes of a tomb-raiding world, starting out in the ruins of Golmud. I activated the sign-in System, and my first reward was the Sixteen-Character Yin-Yang Secret Art. Wu Xie and Zhang Qiling would arrive in three days, but beneath the rubble I found a bloodstained bronze mirror. The collapse of this sanatorium was no accident.