Episode 10 of Mad Concrete Dreams commences with a flashback nine years ago, where Hwal-sung advised Su-jong to purchase the Seyun building. It transpires that Yi-gyeong was pregnant, and Yang-ja had started treating him kindly. With a baby on the way, he sought financial assistance from Yang-ja to buy the building. Unfortunately, Yi-gyeong suffered a miscarriage, and Yang-ja expelled him from their home. She urged him to sever ties with Yi-gyeong. Consequently, Hwal-sung could not secure the funds to pay his share, and his relationship with both Yang-ja and Yi-gyeong began to fray.
In the present, Kim-sun's friend Ae-su intervenes and uses a taser on Dong-chul. With her aid, Kim-sun manages to rescue Hwal-sung from the brink of death. Once Hwal-sung is stabilized, Kim-sun and Su-jong secure his signature on some documents and head back to the Seyun building, leaving Ae-su to handle the aftermath.
Meanwhile, Yi-gyeong attempts to persuade Da-rae to go against her parents, labeling them as murderers. Da-rae counters that it was Yi-gyeong's fault for pushing them too far. Yi-gyeong maintains that they were the ones who pushed her first, but Da-rae insists that one does not need to do wrong just because someone else has.
Kim-sun and Su-jong return to the storage room, where Yi-gyeong lets Da-rae and Kim-sun go. Before Su-jong can leave, she calls Ju-ran, requesting her presence at the Seyun building as she has caught the person she's been searching for. Meanwhile, Ae-su handcuffs Dong-chul to a bar, but he manages to free himself after strangling Ae-su. Realizing that Hwal-sung is not dead, he calls Yi-gyeong. Kim-sun, Su-jong, and Da-rae must flee for their lives as Dong-chul's men pursue them. Da-rae and Kim-sun hide in a locker on the third floor while Su-jong struggles against Dong-chul and his men.
Simultaneously, Yo-na and Dr. Jang are examining the murder scene in Hee-joo's office. Earlier, Hee-joo had offered Su-jong her assistance if needed, so Su-jong decides to take her up on her offer, texting her for help in escaping the Seyun building.
As Yo-na makes her appearance and Su-jong manages to slip away undetected, another disaster begins to unfold within the building. Earlier, Yang-ja had cut the pipes, resulting in a severe water leakage issue. In an attempt to save money on repairs, Su-jong failed to address the extensive damage caused. The leakage led to a short circuit, and soon, the entire building was engulfed in flames.
Meanwhile, Hwal-sung regains consciousness and learns from Ae-su, who had merely fainted, that Yi-gyeong had kidnapped Da-rae and was holding her captive at the Seyun building. Without hesitation, Hwal-sung rushes to her rescue and arrives just as the police and fire brigade arrive at the scene.
Inside the burning building, the confrontation between Yi-gyeong, Su-jong, and Kim-sun has escalated to the rooftop, where Yi-gyeong is holding Da-rae hostage. Hwal-sung enters the burning structure, and his presence further enrages Yi-gyeong, who believes they were all conspiring against her. Hwal-sung attempts to calm her down, suggesting they leave the rooftop and talk elsewhere in private.
Yi-gyeong insists that he should say whatever he needs to before she releases Da-rae. He confesses that the reason he kidnapped Yi-gyeong was to break free from his mother's control. He desired the money so he could leave Yang-ja behind and start a new life with Yi-gyeong. He tells her that he wants to start anew and live a fulfilling life with her and their baby. He wants to protect their baby, just this once.
Hwal-sung's words waver Yi-gyeong, and she reluctantly lets Da-rae go. However, as she steps off the rooftop, she trips and falls. In an instant, Hwal-sung jumps after her, using his body to shield her from harm. He saves her life, but the fall proves fatal for him.
Meanwhile, the clash between Dong-chul and Yo-na continues inside the building. Just as Ju-ran arrives, Yo-na kills Dong-chul. She tries to distract Ju-ran so that Dr. Jang can attack, but Ju-ran reacts swiftly, shooting Yo-na in the ear. Realizing that she has no way out, Yo-na breaks down and presents herself as helpless as Ju-ran arrests her.
Su-jong, Kim-sun, and Da-rae are rescued, while Yi-gyeong is rushed to the hospital. As firefighters try to salvage the shell of his building, Su-jong can only stare at the wreckage in disbelief. Ten hours later, he wakes up in the hospital, according to Ju-ran, who wants him to present himself at the police station for questioning. Su-jong tries to hide the fact that Yi-gyeong kidnapped Da-rae, but CCTV footage proves otherwise.
At the same time, Ju-ran questions Yi-gyeong, who admits that she did kidnap Da-rae and is ready to face the consequences. She insists that Su-jong was responsible for her kidnapping, Dong-ki's case, and her mother's death. She has proof on her phone, and her husband and Da-rae can corroborate her story.
Yi-gyeong learns that Hwal-sung is dead, and she goes quiet with tears streaming down her face. Elsewhere, Su-jong informs Kim-sun that Da-rae will be called in for questioning. He asks her to coach Da-rae on what to say to ensure their stories align. It turns out that Da-rae already has a plan of her own to save her parents and Yi-gyeong too. She has Yi-gyeong's phone and deletes the videos she took of her parents confessing to the crimes they have committed.
At the end of the episode, archaeologists at the previous redevelopment zone find Hee-joo's body and call the police.
