Ghosts Knock on the Door Every Night, I Will Redress the Grievances of the Ghosts in Exchange for Immortality

[Micro suspense + solving crimes + psychic + overlord protecting shortcomings] Lin Wan, who grew up in an orphanage, was diagnosed with terminal cancer the day before her relatives came to visit her. It was also on this night that she heard a ghost knocking on the door, begging her for help in redressing her grievances. The female ghost told her that if she helped her, she could ask Lord Yin Si to grant her two years of life. Lin Wan didn't know if there was really a sinister master, but he called the police on behalf of the female ghost, and sure enough, he caught a fugitive murderer in the room downstairs. The next night, another ghost knocked on the door. She also said that she could ask Lord Yinsi to grant her two years of life. Up to this point, Lin Wan was very busy every day. She was either busy helping Uncle Hat catch fugitives or searching the mountains. She could even encounter robbers while taking a walk and make small achievements casually. Gradually, she found that her illness seemed to be less serious, and even changed from the late stage to the middle stage and then to the early stage. Finally, could she even have eternal life? But she has always been curious, who is Master Yinsi?