A new female detective joins the special investigations team and dives into some of their hardest cases in this follow-up to the series 'Unfair.' Just as a girl asks the team for help finding her missing father, a man calls to say he has four hostages and makes a cryptic request.

Natsumi Yukihira (Ryoko Shinohara) receives secret documents of an organization that controls the country from the shadows. Because of this, Natsumi's ex-husband, Kazuo Sato (Teruyuki Kagawa) pays a terrible price. Natsumi goes back to the Investigation #1 of Tokyo Metropolitan Police Department to take on the organization, but Natsumi becomes involved in a new case. She gets closer to the final enemy.

Akira Mochizuki survived a kidnapping as a child. Now, she's a detective, and there are signs that the kidnapper may be back again after 20 years.

After detective Natsumi Yukihira brings an end to the police hospital terrorist case, Natsumi is transferred to the Nishimonbetsu Police Station in Hokkaido. Meanwhile, a series of grotesque murders occurs in downtown Tokyo involving nails placed in the body of the victims. The fingerprint of Natsumi's ex-husband, freelancer journalist Kazuo Sato, is found on the the body of a victim and Kazuo is placed on the most wanted list. Soon after, Kazuo finds Natsumi and hands her a USB memory stick. The device contains information on a secret organization within the police department. Kazuo tells Natsumi that the series of murders are warnings and suspects become the next victims. Natsumi is then arrested as a suspect. Tokyo prosecutor Katsuaki Murakami appears at the Nishimonbetsu Police Station to investigate.

When a devoted detective probes the suspicious death of her father, she uncovers massive corruption and finds herself in grave danger.

A new female detective joins the special investigations team and dives into some of their hardest cases in this follow-up to the series 'Unfair.' The team investigates a grisly video circulating online that asks viewers to answer 'yes' or 'no' questions with potentially deadly outcomes.