Fang Yi-jen inspects a fingerprint from the scene of a grisly crime and strikes a deal with investigative journalist Hsu Hai-yin.

On a victim's charred body, Fang yin-jen finds evidence that incriminates a construction company. The truth about Yu Cheng-hao's death comes to light.

As police search for Chang Tsung-chien, Fang recalls an incident in Chiang Hsiao-meng's past and uncovers a shocking truth about the recent deaths.

Amid a probe into the death of a man thought to be an ex-con, Fang and Hsu Hai-yin follow the next link in the murder-suicide chain.

As Liu Kuang-yung's fate hangs by a thread, Fang visits a tattoo shop linked to Hsiao-meng and encounters Hsu.

Detective Chao suspects efforts to destroy evidence and exposes Fang's personal connection to the cases. Hsiao-meng leaves a clue for Fang.

Fang and Hsu learn about Chiang Jo-ying's tragic end. As the investigation faces an impasse, Li Ya-chun turns herself in to the police.

Hsiao-meng and Li Ya-chun makes searing confessions about their personal motivations and involvement in the suicide cult. Hsu finds a new purpose.

After attending a mentor's funeral, Fang returns to the police station and finds himself embroiled in two murder cases that happened 15 years apart.

As Fang's solo investigation raises more suspicion about himself, Hsu receives an unusual job offer from the Sevenleaves Foundation.

Following clues from an old photo, the police track down a man named Wu Chun-lu. Later, Fang runs into Hsu at Sevenleaves.

While Hsu starts to question Lin Ming-cheng's integrity, Fang discovers more unsettling leads that point him toward someone he admires.

The investigation reveals a link between the serial killings and a past crime. Fang disregards Hsiao-meng's efforts to help solve the case.

The search for a deserted bus brings the police one step closer to the truth. Fang and Hsu grill Ming-cheng about what happened 15 years ago.

The emergence of a new suspect dramatically redirects the investigation, forcing Fang to race against the clock to locate the serial killer.

With his life at stake, Fang needs to survive a deadly encounter. Meanwhile, Hsiao-meng and Hsu must risk everything to save their loved one.