Enlightening!

"Exactly." Li Yao finished the egg that was fully packed with the soup of pickles and moaned in great satisfaction. He wiped the corner of his mouth with his thumb and said unhurriedly, "Do you know the fatal, fundamental mistake that you and Wu Yaxuan made?"

"Please do enlighten me, senior!" Professor Tang's face was pale. She was in such a trance that she almost fell over. She could not help but hold the corner of the table and struggled to breathe. "It's impossible. It's impossible! Even if Wu Yaxuan's design and my adjustment are not perfect, with negligence of all sorts, how can we be greatly wrong on a fundamental level?"

"The fatal mistake that Wu Yaxuan made was to sell the crystal suit he devised to Zhao Tongtian."