비가 내리는 가을날, 평범하고 조용한 삶을 살고 싶은 수연(이제훈)앞에 인천공항 초유의 폭탄!이라 불리는 여름(채수빈)이 나타난다.

After finding out that Soo Yeon has only been working at the airport for 4 months while she has worked for a year, Yeo Reum becomes enraged. She goes to Team Manager Yang Seo Goon and asks her how she could appoint him as her mentor. However, Seo Goon tells her that if it hurts her pride, she should do well at work because that is the only thing that matters.

평화로운 인천공항에 폭발물을 설치했다는 협박전화가 걸려온다. 여객서비스팀으로 업무에 충실하려는 수연(이제훈)과 성과를 내고 인정 받고싶은 여름(채수빈)은 또 다시 충돌하는데.

Yeo Reum and Soo Yeon get into an argument. She tells him that unlike him, many people including herself need to work their hardest in order for their superiors to recognize them. However, he tells her that she simply has a victim mentality and lacks self-awareness.

오른팔에 통증을 못 느낀다는 수연의 고백을 듣게 된 여름은 계속 수연에게 신경이 쓰인다. 사고뭉치 소리를 듣기 싫던 여름은 고군분투하지만 또다시 고객을 폭행했다는 사건에 휘말리게 되는데…

Words spread regarding a dispute between a passenger and Yeo Reum and a Security Team employee. Because the passenger got a scratch on her face, she has declared that she will sue the airport. No matter how much Yeo Reum tells the others that it was not their fault and that the passenger had attacked them first, she has a difficult time convincing them.

수연이 가진 비밀이 과연 무엇일지 의문을 품는 사람들이 늘어나면서 부담감을 느끼는 수연. 한편 사연이 있는 외국인을 돕기 위해 수연과 여름은 보안팀 직원들과 함께 마음을 합치는데, 이들의 하루는 무사히 끝날 수 있을까

여름의 엄마가 탑승한 비행기가 엔진 화재로 비상 착륙하는 상황이 발생하고, 수연은 여름을 돕기 위해 나선다. 조금씩 여름에게 이끌리는 감정이 생기는 수연, 두 사람은 서로의 마음을 확인하게 될까.

The fire on the plane and the passengers on board are all taken care of. Yeo Reum’s mom gets injured during the process, and she hears someone claiming to be Yeo Reum’s friend help her out. After hearing this story, Yeo Reum looks around to find Soo Yeon, but he is nowhere to be found.

여름에게 좋아한다고 대답해버린 수연. 여름은 수연의 고백에 당황한다. 한편 서인우는 수연의 팔에 달린 장치가 무엇인지 의심을 멈추지 않고, 여름은 수연이 장애 1급이라는 사실을 알게 되는데.

During a meeting, In Woo brings up the topic about Soo Yeon and his support device. He asks Moo Ja to look into In Woo with the excuse that the majority’s safety is more important than an individual’s privacy. Seo Goon tells Soo Yeon about this and warns him to stay low for the time being. When Soo Yeon asks In Woo why he did it, he tells him that he’s going to take him down.

수연의 집에서 하룻밤 신세를 지게 되는 여름. 공항 직원들 사이에서 수연과 여름이 사귄다는 소문이 돌기 시작하고, 여름을 짝사랑하는 은섭은 이를 듣고 화를 내는데..

Seo Goon puts Soo Yeon in charge of persuading In Woo to allow their team to have a lounge area for the workers, and he obeys her. Meanwhile, Eun Seob visits T2 to eat with Yeo Reum. While waiting for her, he overhears a group of employees gossiping about Yeo Reum and Soo Yeon.

수연과 여름의 사이는 조금씩 가까워지고, 은섭은 여름의 출근길에 동행해서 수연에게 자신을 소개한다. 한편 인우는 수연의 일거수일투족을 계속 거슬려하며 둘 사이의 갈등도 깊어지는데..

While chasing a drug broker, Young Joo gets hurt. Instead of chasing the culprit, Dae Gi runs to her and asks her how critical her injuries are. However, Young Joo gets upset and asks him whether he would have done the same if she were a guy. Meanwhile, a fight breaks out between a passenger and a security check employee. In Woo tells the employee to beg in front of the passenger until he decides to forgive him. However, Seo Goon feels differently.

최무자를 구해주다가 부상을 입은 수연은 집밖으로 나가지 못하고, 여름은 수연이 괜찮은지 걱정된다. ‘특별해지고 싶은 게 아니라 평범해지고 싶은’ 수연은 공항으로 계속 출근할 수 있을까.

After the incident, Soo Yeon is told not to use the synthetic arm until he fully recovers since it could worsen his current condition. However, he finds himself missing Yeo Reum too much and decides to leave the house while wearing it. Meanwhile, Yeo Reum finds out that an old man’s son left his own father in Korea.

여름을 만나러 나가던 수연은 또다시 팔에 달린 웨어러블의 고장으로 쓰러지는데, 그 모습을 은섭이 목격한다. 한편 여름은 공항에서 우연히 고등학교 친구를 만나고 몹시 당황하는데 무슨 사연이 있을까.

Min Jung continues to blackmail Yeo Reum, and Seo Goon gets to hear their conversation. A man who has found Dae Gi’s radio keeps fooling around him without returning it. And Dae Gi is told to be on stand-by until he finds the radio back. Meanwhile, Eun Seob tells Soo Yeon to share his conditions with Yeo Reum, but Soo Yeon says he want to keep it secret from her.

팔에 고장이 나는 원인이 바로 한여름이었다고 깨닫는 수연, 두 사람의 감정은 계속해서 가까워지고, 이를 지켜보는 은섭은 속상한 마음뿐이다. 한편 인우에게 수상한 정체의 남자들이 찾아오는데, 인우가 가지고 있는 사연은 무엇일까.

Director Kwon gets to know about the bribe Mr. Lee received from those who are in charge of managing the vans and taxis. He gets furious and questions Mr. Lee about what’s inside in the envelope. Meanwhile, Yeo Reum sees a man threatening a female reception staff with a weapon in the airport. She tries to sort out the situation.

The man who threatened the information desk staff and ended up hurting Yeo Reum runs away. Dae Gi and Young Joo get scolded by Moo Ja for losing him. Soo Yeon finds out that Yeo Reum got injured and was taken to a hospital. He feels frustrated with the fact that there’s nothing he can do for her because he’s disabled sitting on a wheelchair. Soo Yeon decides to take revenge on the man who hurt Yeo Reum.

Yeo Reum, Dae Gi, and Young Joo come to the police station to testify about the incident at the information desk as witnesses. After the testimony, the three and Soo Yeon spend time together having a meal and dessert and riding a rail bike. In the meantime, Moo Ja continues to suspect that Soo Yeon was the one who beat up the criminal with his power.

Moo Ja comes to visit Mr. Jang and ask a few questions about the device Soo Yeon is wearing. In the meantime, Mr. Gong of Passenger Services gets involved in a scandal that he is abusing his power and forces subcontractors to have a drink with him after work. To make things worse, Mr. Gong’s daughter happens to visit his office on the day Mr. Gong is questioned by the Internal Affairs Team.

Mr. Jang suggests that Soo Yeon get a thorough medical check-up because his inflammation level came out too high, but Soo Yeon refuses, saying that he is perfectly fine now. Meanwhile, Soo Yeon happens to see In Woo having a talk with Director Jo who made Soo Yeon severely injured in the past. Soo Yeon gets disappointed that In Woo is still associating with Director Jo.

Incheon International Airport is put on emergency alert as it gets surrounded by heavy fog. Flights from and to the airport are delayed or canceled, and passengers are stuck in the airport. In the meantime, Yeo Reum finds out that Soo Yeon is in serious condition and he's just pretending to be fine.

Because of the heavy fog, all the passengers are stranded at the airport. All the staff at the airport is busy taking care of the delayed passengers. Meanwhile, Soo Yeon shows his resentment towards Mr. Jang for telling Yeo Reum about his condition. When Soo Yeon spends time alone in a park, Director Jo and his subordinates approach Soo Yeon.

Soo Yeon fights against Director Jo and his subordinates. Director Jo gets shocked to see what Soo Yeon is capable of with his arm. In the meantime, Moo Ja keeps trying to find out who’s behind In Woo, and Seo Goon wants to know why Moo Ja is asking around about In Woo.

Soo Yeon gets nose blood in front of Yeo Reum. Yeo Reum tries to help Soo Yeon, but he refuses Yeo Reum’s help and goes to a restroom alone. Then, a group of thugs follows into the restroom. One of them looks familiar to Soo Yeon, and they take Soo Yeon somewhere. When Security Services staff arrives at the mensroom, Soo Yeon is not there. Then, everyone including Moo Ja and In Woo starts to find Soo Yeon.

Dae Gi’s efforts to rescue Soo Yeon at the airport are held back by Moo Ja. Dae Gi and In Woo move out individually to the place where Soo Yeon is taken. In Woo suffers injury while trying to release Soo Yeon from Director Jo, which leads Soo Yeon to use his strengths in order to save In Woo.

Soo Yeon submits a resignation after deciding to leave the airport. Yeo Reum is heartbroken to hear about it from Seo Goon and tries to hold back Soo Yeon from leaving. However, Soo Yeon seems persistent with his decision.