Su Wan, 26 years old, is a museum archivist with an introverted and sensitive personality. He has mild face blindness but has a photographic memory of "details of old objects" (such as handwriting on letters and wear marks on objects). Due to sorting out the old files left by his grandfather (retired police officer), he was involved in the "restart" of the serial murder case 30 years ago. In the early stage, it seemed "ordinary", but in fact, he used his "detailed observation ability" to promote the investigation.
Intention: suspense, thinking