Picking up from the previous events, after Bu Lanyong and Su Zishi fled into the Spatial Rift, they had not taken the corpse of the Frost Dragon with them.
Since this was the head of a divine beast, Shi Lei naturally would not let the opportunity slip by. He stepped out of his own Spatial Micro-World and retrieved the Frost Dragon's head from the core area of the secret realm.
Furthermore, he swept all the Mustard Seed Primordial Spirit Matter near the core area into his Spatial Micro-World.
Chapter 262