Luna covered Leo with a comforter, who had just fallen asleep. He must have been exhausted from meeting his beloved cafe employees who had come to visit. They were all shocked and sympathetic towards Leo's condition, especially Daniel. He merely observed quietly, tears streaming down his face as a sign of his sadness. Thanks to their visit, Leo received many gifts that day. 
Luna gazed at Leo's pale face as he slept soundly.
"He will get better." The voice made Luna lift her head. She gave a faint smile. 
"Ariel." 
"I'm sorry, I just came today. I've been a bit busy with company projects," Ariel said, sitting next to Leo. 
"It's okay. We understand. But Leo just fell asleep. You want to…" 
"No, it's fine. I just came to drop by for a bit. Let him sleep. How about you? Are you alright? You look thinner. Luna, if you want to take care of Leo, you need to prioritize your own health. How can you take care of him if you're sick?"
 "I know. It's just… I haven't had much appetite lately. I don't want anything else in this world anymore, Ariel. I just want Leo to get better. That's all."
 "I remember what Leo said before he married you. He asked me to promise something. Leo said if anything happened to him, he wanted me to take care of you, even though I thought it was impossible because I knew your love for him would always be strong. Then I replied, if he stayed stubborn, I would take you away from him, even if he was still alive. After that, he decided to tell you about his illness and start treatment again. He was terrified I'd take you," Ariel chuckled. 
Luna smiled. 
"You're right. No matter what happens, my love for him will always remain strong. After my memory returned, I realized how I couldn't live without him by my side. Every time he sleeps or closes his eyes, I get so scared. Afraid that he won't open them again. Just imagining it makes my heart ache..." Luna wiped her tears. 
"Leo will get better. Trust me. He is my cousin. I know him better than anyone. Once he decides to fight, he will keep fighting until the end. Believe in him, Luna," Ariel advised. 
Luna nodded.
 "Thank you. I believe in Leo. I believe he will recover." 
"Great. I have to go now. If you need any help, just call me. I'll help as much as I can." Luna smiled and nodded. Ariel patted Luna's shoulder before leaving Leo's room. He passed by Mark, who had just entered. "Are you okay?" Mark asked when he saw Luna's red eyes. 
"I'm fine." Mark looked at Leo for a long time, then his forehead creased. His eyes widened as he pulled out a folded piece of paper from under Leo's pillow. 
"What's that?" Luna asked. Without answering Luna's question, Mark unfolded the paper, and his expression changed. 
"Why? Is there something wrong?" Luna approached Mark and read what was written on the paper. Her eyes widened.
'ISN'T IT HURT? LET ME HELP YOU LEAVE THIS WORLD PEACEFULLY'
"What... what is this?" Luna trembled as she read the note.
"Who came earlier, Luna? Who visited Leo?" Mark asked urgently. Luna was still in shock, silent and motionless.
"Luna!"
"The... Cafe staff. All the Cafe staff and..."
"And?"
"Ariel."
Hearing this, Mark pulled out his phone and dialed a number.
"Michael, I need you to send your people to the hospital right now. It's important. Okay, I'll wait. Don't take too long." Mark ended the call.
"Mark, what does this mean? That paper... It's not the same paper..." Luna glanced towards Leo.
"Let's talk outside."
"What's happening, Mark?" Luna asked as they stepped out of Leo's room. She sat down, her body shaking with fear, remembering the words on the note.
"I need to know, Luna. Is what you said about Adam earlier true? Is he really a murderer? You were a witness. You must know something." Mark looked anxious.
"I saw him stabbing the victim repeatedly. Why? What's the connection between Adam and that note?" Luna's voice trembled.
"You'll find out soon enough. Hold on, I'm waiting for someone."
After about fifteen minutes, two large men arrived, their appearance intimidating like gangsters.
"I want you to watch over Leo. Don't let anyone into his room except his family. Understand?" Mark instructed. The two men nodded silently.
"Let's go." Mark gestured. Luna complied. Mark led Luna to another apartment of Leo's, one she never knew existed. When Luna stepped inside, she saw the living room was cluttered with papers, and the walls were covered with various pictures and newspaper clippings.
"What... is all this?"
"As you can see, this is Leo's apartment and our investigation base. No one knows about this place except me and Leo. Leo told me if anything happened to him during his treatment, he wanted me to show you this apartment. All of Leo's secrets are here. Given what you saw on that note, now is the right time.
Luna read one of the newspaper clippings on the wall.
'COLLEGE STUDENT FOUND DEAD'
She read another clipping.
'DECAPITATED BODY FOUND'
All the clippings were related to murders.
"Explain to me. Why are you and Leo investigating all this? What's the connection between these cases, the note Leo received, and Adam?"
"Sit down, and I'll explain everything."
Luna sat on the sofa. Mark placed a cup of coffee on the table.
"It all started with the notes Leo received. You've seen those notes, right? And today, you saw one under Leo's pillow."
Luna clenched her trembling hands.
"How? How did that note get there?"
"No doubt, it must be someone who visited Leo today." Mark sighed.
"Who? Who exactly is this person?"
"Remember, you were a target, too, right? If Leo hadn't saved you that night, you wouldn't be here, Luna. Leo might not have told you, but the notes never stopped coming to his house, even now. All this time, Leo and I have been investigating who the sender is. Is the person the same one who tried to kill you? We didn't get any answers until the pictures of the victims you saw on the wall were sent to Leo. Those pictures were never released to the public and weren't even in police records. Right now, the police are actively investigating a serial killer. The killer keeps one of the victim's body parts, and you know what? The pictures Leo received are of those missing body parts. Do you know what this means?"
Luna's body shook as she listened to Mark's explanation.
"You... You mean the person who killed all those victims is the same person who..."
Mark nodded, his expression grim.
 "Yes, the person who tried to kill you and the person who sent the notes to Leo... It's the same serial killer. Do you know why, Leo? Out of all people, why did the killer send those pictures to Leo? And why did the killer try to kill you? And today, you said you saw Adam stabbing the victim repeatedly behind the cafe? Are you sure about what you saw?"
"I am sure. I definitely saw Adam."
Mark exhaled sharply. 
"Luna, the person you saw getting killed was the second victim. She was found behind the cafe, the same place you had seen. But if Adam was the killer, who killed the third and fourth victims? Adam wasn't around at that time, Luna. Do you think it's logical for Adam to send all those pictures to Leo? Adam is dead, Luna."
Luna was stunned. She fell silent, trying to recall everything clearly, but her memory was not wrong; she did see Adam. But Mark's words also made sense. Who killed the third and fourth victims if Adam was already dead?
"But your memory isn't wrong, Luna. It's just..."
"Just what?"
Mark took out his phone and showed Luna a video recording.
"This is a video recording that Leo set up in your house. In the recording, there's the face of the killer."
Luna played the recording, and her face changed.
"Mark, this... it can't be..." Luna covered her mouth in disbelief. The recording showed Adam's face, but...
"That's why Leo suspected something after he saw the recording."
"Suspected what?"
"Most likely, the person in the video is Adam's twin, and Adam is colluding with his twin. The person you saw that night was also Adam's twin. You said your head was hit after you witnessed the murder, right? Leo's guess might be correct. The person who hit your head might have been Adam himself. He likely wanted to protect his twin."
"This is all impossible..."
"And another thing, you were in a car accident, right?"
Luna nodded.
 "I had an accident because there was an issue with the car. Suddenly, the brakes failed, and I lost control."
"Don't you think the car malfunction was intentional? Adam died trying to save Leo from being hit by a car. And you had an accident because the brakes failed. Don't you think it's too planned to be a coincidence?"
Mark's words made Luna rethink everything. She had never suspected that her accident was intentional. If Mark's theory was correct, then the killer planned to kill both her and Leo. But why? What did they do wrong?
"Right now, I'm still investigating Adam's twin. I'm a hundred percent sure he exists and is the actual killer the police are looking for. The video recording you saw was staged. He deliberately showed his face because he wants us to find him before he finds us."
"Do the police know about all this?"
"Of course. Leo is working with a police officer on this case."
Luna bit her nails. She never expected the situation to be this dire.
"I need you to listen carefully, Luna. The killer we're dealing with is not just anyone. He must have an accomplice. So you must be careful."
"An accomplice?"
Mark nodded.
 "I believe his accomplice is someone we know, and it's the same person who put that note under Leo's pillow. For now, all of Leo's Café staff are suspects. Including... Ariel."
"But it can't be Ariel. He wouldn't do that to his own cousin." Luna didn't want to believe it. Ariel seemed so kind to Leo, even sacrificing his own feelings for Leo's happiness.
"Don't trust anyone, Luna. We don't know if there's an enemy in disguise. Sometimes, what we see isn't always the truth. I'm sure it's one of them." Mark pulled out his phone and dialed another number.
"James, I sent you pictures of a few people. Have your men follow all of them. As soon as possible. We're getting close. Don't stop until we catch the killer. Okay. See you later." Mark ended the call.
"Luna, I need to go meet the detective for a bit. Stay here until I return. This place is safe, don't worry. If you're hungry, you can eat whatever is in that cabinet. Remember, Luna. Don't go anywhere. You and Leo are both in danger right now. I'll contact you if anything comes up." Mark hurried off.
After nearly half an hour of waiting, Luna was restless, unable to sit still. Her thoughts were on Leo. Even though two people were guarding Leo at the hospital, she still felt uneasy. Luna bit her nails. From sitting, she stood up. Mark had mentioned that this apartment held all of Leo's secrets. What secrets was Leo hiding from her? Luna suddenly felt curious.
The apartment had three rooms. Luna stepped into the first room. It was just Leo's bedroom. Luna sat on the edge of the bed, noticing how modestly it was decorated. She glanced at the small table beside the bed and opened the drawer. Inside was a black-covered book. Without thinking, Luna took it out and frowned.
"Is this Leo's diary?" Luna smiled wryly. She opened the first page, and as she suspected, it was indeed Leo's diary. Luna took the diary out. It must contain many stories about the woman who had been in Leo's heart before he met her. She couldn't wait to read it. Luna then opened the door to the second room. There was nothing in it except another bedroom and a shelf filled with files. She closed the door again and moved on to the third room. Her expression changed.
The third room was smaller than the first and second rooms and was filled with framed pictures of her on the walls. Each image had its own label. Luna walked over to a label titled,
 LUNA AT 16 YEARS OLD.
Each photo had a date below it. Luna covered her mouth in shock. She examined the pictures under that label and realized that most of them were from before she had feelings for Leo.
Leo liked her first?
Luna's eyes landed on a picture at the bottom.
"The library photo..." Luna whispered to herself in shock.
So Leo was there watching her?