A mysterious woman asks Shen Yi to draw how a child in a photo would look as an adult; seven years later, Shen Yi receives a call from Chief Zhang of North River Police, helping them catch a criminal by creating a sketch over the phone.

He Rongyue confirms Liang Yi died of cyanide poisoning; Du Cheng briefs Chief Zhang, who orders them to find the five missing plastic surgery patients; Du Cheng asks secretary Liu Yun to match faces before and after surgery with medical records.

Chief Zhang is pleased with the quick case resolution; Du Cheng unexpectedly accepts Shen Yi's addition to the team and offers to help him learn the job at crime scenes; at the police station, witness artists recognize Shen Yi's distinctive style.

Investigators prioritize determining when the skull was replaced and interviewing Ren Xiaoxuan's classmates; Ren's mother provides her daughter's diary, revealing bullying incidents and a close relationship from high school.

Shen Yi and Du Cheng find multiple banyan tree paintings by Ren Xiaoxuan; one painting bears her red lip print overlapping with another, likely belonging to the mysterious boy; after the case, Du Cheng visits Lei Yifei's portrait to honor his mentor.

Chief Zhang briefs on Chu Yingzi's case, a death row inmate who claims an uncaptured accomplice coerced her into murder through marriage fraud; victims' families protest regularly; multiple sketch artists produce different images.