Soon, he had returned to Chu Yuyan outside the fissure-like cave. Her face was pale, and she was concentrating on the pill furnace. She took out some medicinal plants, squeezed the juice out of them, and then placed them in the furnace. Meng Hao sat down cross-legged a short distance away. A look of deep thought appeared in his eyes. He took out one of the skulls he had just acquired and examined it closely.