As ViCAP finally gets the green light to raid Alastor Pharmaceuticals, Clarice punches another FBI agent in a moment of rage, then willingly turns in her badge and gun. Also, the rest of the ViCAP team uncovers the whole truth about the River Murders, and Clarice unwittingly puts herself in mortal danger.
The death of Superintendent Jung becomes a boomerang and starts to inflict damage in all sorts of places. While Lee Chang Jin becomes the main suspect and gets arrested once again, confessions, names, and stories from others involved start pouring out. Meanwhile, Ju Won heads to get Jeong Je out of the hospital his mother put him in.
Shocked at the incriminating words his father spoke, Ju Won, full of tears, lets Dong Sik hear the recording. He promises to take down his father and stops Dong Sik from his rage-driven madness. They agree to work together and lay a trap for Han Gi Hwan, hoping he gets appointed as Commissioner General. Meanwhile, they question Lee Chang Jin one more time.
Dong Sik arrests Ju Won, throwing everyone into confusion. However, Ju Won sets up a trap for the beast and gets closer and closer to the center of the truth. Meanwhile, Jeong Je fools his mother and exposes her and Lee Chang Jin with Dong Sik listening to every word.
Jeong Je reveals everything he remembers about how he hit Yu Yeon with his car to Dong Sik. But what he describes contradicts what Dong Sik knows. He lets Jeong Je go to his mother, Councilwoman Do, to pass on a few words of his. Meanwhile, Chief Superintendent Han gets nominated as the next Commissioner General.
Everyone in Manyang and Munju seems to be mixing lies with the truth, and trust with suspicions. Dong Sik and Ju Won tenaciously carry out their investigation, putting pressure on the suspects. Meanwhile, Jeong Je begins to lose his grasp on things as memories of the past continue to haunt him.
Why did Sang Bae have to die? Dong Sik and Ju Won overcome their sorrow, and they become determined to find out the secret behind Sang Bae's death. The digger they deep, the bigger the secret. Meanwhile, they suspect Gil Gu, who won't tell them the truth.
Hyeok goes to see Ju Won in Busan and ends up provoking him. Meanwhile, Chief Nam Sang Bae is named a suspect in aiding and abetting Kang Jin Mook’s suicide. Ju Won and Dong Sik butt heads over Dong Sik’s suspicions of Ju Won framing Chief Nam. Later on, Ju Won engages in a chase, and when Dong Sik catches up to him, they are met with a shocking scene.
Ju Won is back after his leave to not Seoul but to the Manyang Police Station. As soon as he’s back, he keeps his eyes on Officer Lee to dig deeper into the real cause behind Kang Jin Mook’s death. Meanwhile, many bodies were found at a deer farm.
Jin Mook is arrested, causing an uproar all across Manyang. People start to wonder whether it was just Min Jung or all the other missing women whom Jin Mook killed. Trying to get a confession out of Jin Mook, Dong Sik and Ju Won make a risky deal. It seems the partners now have no choice but to work together.
Dong Sik and Ju Won start a separate, unofficial investigation of Min Jung’s disappearance. However, some people don’t seem to be interested in the truth. They only make matters more complicated with their selfishness. As his friends face trouble, Dong Sik becomes enraged and makes up his mind.
Ju Won’s surprise press conference causes a stir, but things don’t go the way he expected. Meanwhile, Congresswoman Do and Lee Chang Jin go ahead with the redevelopment as planned, even using Jin Mook in an event. When Dong Sik finds out, he goes berserk and heads straight over. Later, Ju Won presses Dong Sik with a new secret he discovered.
Manyang, a once peaceful town, becomes engulfed with sadness and fear. As the investigation to locate Kang Min Jung proceeds, Dong Sik shows his sly side, and Ju Won get put in a tight spot. Dong Sik continues to provoke Ju Won, causing her to become inflamed. Meanwhile, a worthy clue turns the situation around.
Dong Sik and Ju Won’s difference in opinion regarding the skeleton seems too great. Meanwhile, Ju Won chases after Dong Sik, and Dong Sik digs into Ju Won’s past. Their mutual distrust only seems to deepen. When they go out to have a look around the town together, they come across a shocking scene.
Manyang is a small town on the outskirts of Seoul and is usually quite mundane. Dong Sik, a police officer who works at the substation there, is known by the nickname, “the nut case”. One day, Ju Won, an elite officer from Seoul, arrives in town. Dong Sik and Ju Won couldn’t be any more different, but they end up becoming partners. Then, a skeleton appears before them.
Kate and Jeanette's worlds collide as the court date arrives, finally forcing the two young women to answer the question on everyone's mind, but the answer comes with a price that not everyone can pay.
Cecile is forced to confront her past in order to break free from a psychic prison. Meanwhile, Chester takes over for Cisco but makes a mistake that puts Barry in serious danger. Joe investigates Kristen Kramer's old military ties and discovers an unsettling truth.
Jack and Annie hijack a middle school party thrown by the cool kids, to which Kimberly wasn’t invited. They then devise a plan to get the kids to their house, so Kimberly can “up” her popularity game, but things get out of hand. Meanwhile, Duncan and his friends work on creating a viral video, so they can become the next internet sensations.
When Spencer's quarterback must miss the game against Westlake, Spencer puts extra pressure on himself and his young teammates because of what is at stake. Billy and Jordan grow worried when Willie doesn't show up to the game as promised and Billy learns something about Willie he wasn't expecting. Laura must deal with a new wrinkle at work that involves Olivia leaving Laura with a tough decision. Meanwhile, Spencer takes a walk down memory lane as Coop's 18th birthday nears and Layla and Preach clash over how to celebrate Coop.
Mick takes the Waverider and Kayla to try and find Sara, but these enemies find themselves needing each other to survive after landing on the possible planet Sara is being held captive. After a report of an Alien attack, the Legends return to their new headquarters where both Spooner and Astra try to connect to the Alien. Meanwhile, Sara devises a plan to escape by using her charm to win over Bishop.
Kevin, bummed from being stood up by Jasmine and ripped off by a local Brooklyn rapper, spends a ’shrooms-filled night out with his successful sister which leads to a series of revelations. Meanwhile, in an effort to make Dan bond with his stepdad Kareem, Dan’s mom drags him into competing in the Greenest Block in Brooklyn contest.