Li Chengshuo had found quite a few spiritual objects during her days in the Secret Realm, but it was by chance that she came across a three-zhang-sized Black Stone, completely covered in Array Patterns.
Originally wanting to take the Black Stone with her and study it in detail after leaving the Secret Realm, she found that it couldn't be put into the storage ring.
This unusual circumstance immediately caught Li Chengshuo's attention, and, since she had been intending to study Array Patterns, she stopped right there to focus on the Black Stone instead of exploring the realm any further.
Perhaps it was because her skills were lacking or maybe the Array Patterns were too profound—after pondering for such a long time, Li Chengshuo managed to discern only a little about the spatial-related Array Patterns.