Krystal arrived in a small city where she rented a room. She doesn't know what she'll do or where she'll be going. All she knows is that running away is the best option she has.

Kai kept calling her but she opt not to answer. 

She never expected that the mistake she made when she was 8 years old will backfire. The past that she longed to forget has been haunting her.

Her phone rang again but this time, it isn't Kai's number flashing on the screen.

"H- H- Hello?" Krystal nervously answered.

"Why do you sound so scared, darling? Miss me? Tsk. Tsk. You tried running away." the voice from the other line said sarcastically.

"What do you want? And how did you know my number?"

"So fierce... I'm just here to get what is meant for me..."

"Then it has nothing to do with me..." Krystal answered.

"Uh uh, you're mistaken... I could have had everything you have."

"It was a long time ago... I'm sorry for what happened." she honestly said.

"What will your apology do? You can't bring back all those time I lost. Now, you have to pay."

"I'm sorry. I'm sorry."

"Too late... I'm here to collect the debt you owed me... Make sure you'll pay in full. See you soon."

"Wait!"

The call was ended and Krystal looked a lot gloomier.

"I'm sorry..." She whispered as she cried alone.

[Meanwhile]

"Kai..." L called out as he went into his brother's room. He was discharged from the hospital but Chanyeol is still unconscious. He watched his brother pack his bags. "I know I'm in no position to ask you this... but please, talk to Umma before you leave. She... She's crying in her room. She feels so guilty."

"Hyung. We've talked about this. I'm not ready yet..." Kai sighed. "I will talk to her once I come back, arasseo?"

"But..."

"You're scared that I won't be coming back... Don't worry, hyung. I'll be back once I find Krystal."

"I know you'll be back. I believe you'll be back with her."

L finally agreed to his brother's suggestion that Kai will look for Krystal. Even though Kai doesn't know where to start, he has a hunch on the first place Krystal will go.

Kai eventually left without speaking a word to his mother. He felt that it isn't the time for them to talk. He rode the train as he started the journey that might lead to nothing in the end.

[Fast Forward]

It has been a month since Kai left but there were no phone calls, no messages, nothing... L was getting impatient but he knew he had to follow their deal. He has to wait. He has to be patient. He trusts Kai with his life and he believed in his words. His brother will come back with the girl he loves.

"Princes