Dou He had followed Li Shun and Zhou Jian to Daxing. Initially, when Han San was taken to the Liaodong Rong Tribe to detoxify, there were rumors she never went there but instead went to a different place to detoxify and heal. Later, General Mo, the Military Justice General, did not reside in Capital Jingcheng but opened a mansion in Daxing, a half-day's journey away. Han San, who should have been favored by the Emperor and beloved by the people, seemingly disappeared without a trace, with no news whatsoever.
Therefore, Dou He had always suspected Mo Heng because he himself harbored unsavory motives, which made it clear to him the untraceable forbidden love Mo Heng was involved in. He must know Han San's whereabouts!