When Qi Haoran and Fan Zijin learned that the mastermind behind the poisoning of the East Hall couldn't be found, their expressions darkened. However, the two of them knew that the most anxious person should be the Emperor, so they did not say anything. Still, the two of them began to slowly investigate in private.
The two of them seemed to know what the other party was thinking, so they did not waste any resources. They directly put their heads together and investigated together.
However, even Qi Xiuyuan couldn't find anything after two to three days, let alone them. Qi Haoran returned home later and later, and his expression increasingly darkened.