Two months after her parents' tragic death, Chin had settled into her new, minimalistic apartment. It resonated with her unassuming taste, and Elly had been a tremendous help with the move. As Chin rested in her new space, her phone rang, and it was Elly on the line.

"Chin, do you need anything?" Elly inquired.

Chin replied in a rather peculiar tone, "No, Elly. I think I just need some rest."

Elly chuckled and said, "Your reply is always the same. Alright, rest in peace."

As soon as Elly ended the call, a knock echoed at Chin's door. She hurried towards it, as if anticipating someone's arrival. Upon opening the door, she was greeted by a young man named Alex, whose lively personality contrasted sharply with Chin's reserved demeanor. Chin welcomed him with an unusually radiant smile.

"Alex, you're finally here!" Chin exclaimed, her eyes beaming with happiness. "You don't know how much I've been waiting for you."

Alex grinned broadly and teased, "My big monster has grown so well, but you still look more like a guy than a girl."

Chin laughed with a genuine sense of purity, a sight rarely seen throughout her life. Alex was Chin's best friend, a person she trusted with her life. They had met in their adoption center, sharing everything before Alex was adopted and moved to New York. Despite the distance, they had stayed connected through emails.

They talked for hours, reminiscing about old times. Eventually, Alex handed Chin a file, his expression turning serious. "Chin, I don't know why you're getting involved in this, but please be careful. I can't afford to lose my one and only friend."

Chin replied earnestly, "I'm surprised you never made other friends, Alex, but you know no one can understand you the way I do."

Alex gave her a sly side-eye and remarked, "Only a monster can understand a monster." They both shared a nostalgic giggle, reminiscent of their days in the adoption center.

After Alex's departure, Chin opened the file, muttering to herself, "Where are you hiding? But remember, I will find you, even if you're hiding under a black rock on a moonless night."

Meanwhile, Taewoo and Hazel made progress in their case involving a man named Lee Sung, a watchman at the agency where the map had gone missing. He confirmed that the map had been stolen four days before the deaths of the four architects in Korea. Authorities had tried to keep it confidential, but the deaths had blown their cover. Furthermore, Mr. Kate had left Korea four days before the incident and resigned one day before it. His records in England had mysteriously vanished, making it difficult to trace who had met him after his arrival and who had taken the map.

Mr. Mark, on the other hand, reached out to Chin. When she answered the call, he remarked, "I thought you'd be eager to find out who has the letter, but I think you cannot find me because I don't leave a trace behind, except when I want to save someone."

Chin, in a bewildered tone, asked, "Who are you?"

Mr. Mark rose from his seat and replied, "I'm the only loyal person. You can call me your savior. Remember, I met you and left a card at your place. Do you still have that card?"

Chin's voice quivered as she questioned, "Why do you have the letter, and what do you know about me?"

Mr. Mark responded confidently, "I know everything about you, what my dad told me and what he didn't tell me. This is my way of dealing."

Chin demanded, "I need that letter. Where can we meet?"

Mr. Mark cryptically replied, "The place where the devil buries his sins."

Chin cut the call, determination in her eyes. "Okay, we'll meet there."