In Book Five of the LUK SIU FUNG series, all of the wulin figures who fled into the Haunted Valley did so because they had been targeted for death by powerful enemies.
One such individual was Dook Goo Mei, whom Luk Siu Fung encountered while fleeing from Sai Mun Chui Sheut. Dook Goo Mei needed to hide in the Haunted Valley because Yip Goo Hung (cousin of Yip Goo Sing) and the Pink Swallow both wanted to kill him. The Pink Swallow, however, was murdered by Yip Goo Hung, and Yip committed suicide shortly after being defeated by Luk Siu Fung and realizing that he could never compete against Sai Mun Chui Sheut.
With both his enemies dead, did Dook Goo Mei really need to enter the Haunted Valley anymore? He ended up going there, but if those who were trying to kill him were dead, shouldn't he have just turned around and headed home? There was no more need for him to go hide in the Haunted Valley.