"Very simple. Normal liquid flows along the rock face, and when it encounters a protrusion, like a rock, it will definitely flow around it before continuing downward."
Chu Ying wore a faintly amused expression. "Yet the traces of blood flowing down the rock face did not follow this simple rule. Understand?"
"This subordinate understands. That is equivalent to water being unable to flow upward. Therefore, was this blood smeared on by artificial means?"
Chapter 48