Baek Beom, a medical examiner, performs an autopsy on a young victim. Cha Soo Ho, a detective, watches the procedure from behind a glass. He mentions the disappearance of the victim’s underwear and skirt and tells Beom that the victim was raped and murdered. However, after a short while of examination, Beom tells him that it is a car accident disguised as rape and provides medical evidence.

Eun Sol, a newbie prosecutor, holds hands with Baek Beom and Cha Soo Ho to investigate a murder case of a conglomerate’s son’s wife. Sol and Beom specu-lates that the husband beat her, who was pregnant, to death. However, Beom tells her never to trust the corpse itself because once a body decomposes, new scars may show up, and existing wounds may vanish.

Eun Sol is shocked to see Baek Beom stand as a witness for the conglomerate son, Oh Man Sang. Beom testifies that the cause of Kwon Hee Kyung’s death is not assault. Meanwhile, due to the lack of evidence, the trial is postponed for three days. Will Sol be able to find more evidence to prove that Man Sang is the killer, or will Man Sang be set free?

Although the trial seems to be leaning in the defendant’s favor, Sol does not lose heart and begs Beom to analyze the heels that she wore to the crime sce-ne. The results show that on the carpet where Hee Kyung was found, traces of pills are found. Sol immediately believes that Man Sang has replaced the con-tents of Hee Kyung’s pills into those that would kill her.

Sol进行了第99次相亲，对这个自卑的妈妈的男孩印象不深。对于他的母亲，她整个约会都在看着他们，并给了她300万美元，以说服她嫁给他，Sol告诉她，她的儿子应该学习如何培养自尊，并弄清楚自己的生活。与此同时，Deuk Nam的三个姐妹发现她们兄弟的尸体不见了，并发了神。

Sol怀疑已故的Jang Deuk Nam的死亡是一起谋杀案，他起诉他的三个姐妹和他的妻子Choi Hwa Ja谋杀。 与此同时，在与Kang Hyun谈论谋杀案时，Hyun告诉Sol不要太信任Baek Beom。 当她问他和Beom之间是否有冲突时，他只是警告她要小心。

Baek Beom在死去的Byun Soo Kyung的衬衫上发现了Choi Hwa Ja的指纹。他立即打电话给Kang Dong Sik，问Eun Sol在哪里，却发现她已经离开去见Hwa Ja。Beom疯狂地拨打了Sol的电话。与此同时，在向Sol挥手并告诉她进来后，Hwa Ja在Sol的饮料中混合了一种未知的物质。

Choi Hwa Ja所做的所有恶行都被揭露了，尸体原来不是Jang Deuk Nam。 此外，Hwa Ja身边有一个情人，尸体属于那个人。 据透露，Hwa Ja因为遗产而谋杀了这两个人。 尽管结果声称Hwa Ja的孩子实际上是Deuk Nam的，而不是她的爱人，但Sol要求做出严厉的裁决。

Soo Ho的鞋子在Yeon Mi Rae的家里被发现，Yeon Mi Rae被发现已经死亡。Sol和Dong Sik立即去他家，发现他身上有酒精的气息。Soo Ho作为嫌疑人被带到警察局。当Dong Sik问他昨晚发生了什么时，Soo Ho告诉他他不记得了。

他们找到的所有证据都指向Soo Ho。虽然他无法回忆前一天晚上的太多，但他恳求他没有杀死Yeon Mi Rae。由于Sol与Soo Ho的关系，Kang Hyun被任命为该案的首席检察官，Sol只被允许与他合作。虽然她找不到任何能帮助Soo Ho的确凿证据，但她觉得他不是凶手。

事实证明，凶手实际上是Mi Rae的男朋友Kim Joon Tae，团队成功逮捕了他。Sol问Joon Tae他杀她的原因，他告诉她那是因为他爱她。此外，Joon Tae承认他是如何看Soo Ho几天的，以弄清楚他的模式并陷害他。与此同时，Hyun告诉Sol他的第一个病例。

这一次，Sol和Beom面临着一起车祸案件。汽车司机Choi Mi Jin在事故现场死亡，而她的男朋友Jeong Ji Hoon毫发无损地出来了。在进行Mi Jin的尸检时，Beom觉得很奇怪，并告诉Sol，Mi Jin从一开始就不在车轮后面。

While helping Beom with the autopsy of a man suspected of MERS, Sol feels faint and gets her palm cut by a scalpel. Not being able to get any help from an-yone outside due to being quarantined, Beom stitches her palm himself. Hyun rushes over to the autopsy room and becomes enraged by what has happened to her.

While inside the autopsy room, both Sol and Beom start to feel sick. They both suffer from a fever, and Beom even collapses. The NFS goes to late Lee Dong Jae’s place, and Hyun finds out that Dong Jae had a sizable life insurance. Now, the cause of his death could either be due to an illness or murder. Mean-while, another secret is revealed regarding Beom's past.

Kang Hyun meets Baek Beom while commemorating his late, older brother, Kang Yong. Beom finds out that Hyun is Yong’s younger brother, and Hyun tells him that he will make sure he pays. Meanwhile, a young boy’s corpse is brought into the autopsy room. As if it’s not depressing enough, the corpse turns out to be Ma Do Nam’s son.

Do Nam and his wife mourn heavily over the loss of their son, Sung Jae. Initially, Sung Jae is believed to have fallen from a building. However, judging by the absence of blood at the crime scene and how the top of his head hit the ground first, Beom and the crew suspects this to be a homicide, not an accidental fall.

Sol remembers seeing many different pill containers on Sung Jae’s desk. After confirming that Sung Jae was alone during the time of the accident, she visits Sung Jae’s roommate, Park Jun Ha, and apologizes for suspecting him. Feeling understood, Jun Ha tells her exactly what happened on that day.

Right when Beom is about to perform an autopsy on Seo Jeong Min, Kang Hyun’s colleague, Kang Hyun suddenly stops him from doing so. He tells Beom that he is not allowed to perform the autopsy in case of destruction of ev-idence. When Sol asks why he is being so cold toward Beom, Hyun tells her that the last person Jeong Min talked to on the phone prior to getting killed was Beom.

As all the evidence of the murder points to Beom, he is taken into custody as a suspect. Furthermore, he decides not to explain himself which does not do well for him. Those who have been working close to him cannot and does not believe that Beom is the true suspect of this crime. However, Hyun is more than just determined to indict Beom once and for all.

Eun Sol arrives too late and finds the body already in the process of cremation. However, Beom tells Hyun that if he can obtain even one piece of the bone, the autopsy can be performed. Hyun, who’s hesitant at first, orders the body to be brought to the NFS. Dong Sik doesn’t understand why Beom is so determined to prove that it’s a homicide since that will only make Beom himself suspicious.

It turns out that the real murderer is actually a woman. Hyun confesses that he omitted some parts from the late Seo Jeong Min’s call history and that he knows who the murderer is. The team makes an urgent, public arrest for Lee Hye Seong, and during the interrogation, she explains that she had been threatened by Jeong Min.

Yeom Sang Goo, a 76-year-old man, is found dead in his sleep. Although shocked by their father’s sudden passing, his three children prepare for the funeral. However, they seem very suspicious. They decide not to report his death and go straight to the funeral hall. In addition, they do not seem to mourn for him and even ask the doctor to write up his cause of death as a heart attack.

Dae Sik is taken into custody and is interrogated after being suspected for mur-dering his own father. It turns out that he is seriously addicted to bitcoins and also suffers from anger management issues. Meanwhile, a dead rat is found at Sang Goo’s place, and Beom decides to perform an autopsy on it. This brings an unexpected result.

It turns out that the amount of poison the late Yeom Sang Goo took was minimal and thus, he did not die due to that. The team is back to square one and begin the investigation all over again. Meanwhile, Eun Sol obtains footages of both Sang Goo’s son and daughter taking him outside of his home. She also finds out that Sang Goo left around 600,000 to 700,000 dollars in inheritance.

While grilling some pork skin at a restaurant with Beom, Sol suddenly has an epiphany and asks for surveillance footages of Yeom Sang Goo’s area on the day of his death. Although Sang Goo’s children have done nothing good, their physical altercations with their father fails to prove to be the cause of death. Meanwhile, Sol finds an important lead.

Prosecutor Do Ji Han firmly believes that the killer is the same killer from 30 years ago, and therefore, is a serial killer. Realizing the graveness of the situa-tion, a new team is formed solely for this case, and Pyo Yoo Seong takes the lead. Although Sol repeatedly tells Ji Han that they cannot ignore the possibility of a copycat, Ji Han refuses to listen.

The body of Seong Hye Bin, a young woman, is found in the mountain by a hiker. Beom notices that her limbs are tied with a knot and that her fingerprints are missing. He also meets with Deputy Chief Prosecutor Do Ji Han, but the two do not get along at all. Ji Han tells him that the culprit is a serial killer.

Lee Kyung Ja, a past victim and survivor of the Wuseong Serial Murder case, is found dead. Pyo Yoo Seong leads the autopsy himself while Beom grudgingly obliges to be his assistant. During the autopsy, Beom smells something odd and starts sniffing around. Meanwhile, news reporters ask Do Ji Han if he is to blame for the death of Kyung Ja.

The team begins narrowing down the culprit. They compile a list of home addresses where the water usage has been unusually high. While investigating, Ji Han finds Detective Choi Hyun Seok’s wheelchair and a rifle bore-cleaner next to it. Suddenly, Oh Jong Cheol, another detective, greets him warmly and invites him over to his house.

Baek Beom finds out the truth behind all the events that had occurred in the past. Man Sang is called into the prosecution once again when his lawyer was found dead in her car. Eun Sol is convinced that Man Sang is behind her death, but there is no evidence to support it. Meanwhile, Beom takes his first vacation in 10 years.

They have all the suspicions, but none of the evidence. All the puzzle pieces of Han Ji Won’s death don’t fit to find a cause of death. However, Beom goes through all the autopsy records to figure it out and help solve the case.