Inspector Cho Kyuhyun had just reached his home after a tiring night of interrogating the latest suspect of a murder case. He was about to remove his jacket, when his handphone vibrated. 

"Yes, Hyuk? I just reached home" Kyuhyun put his phone on  loudspeaker. 

"Sir, there's another murder, same pattern. Donghae and Ryeowook are going to the scene now. So it can't be the latest suspect, right, coz he's still in our custody" Hyukjae said in a rush. 

Kyuhyun took a deep breath and scratched his head "This is so annoying. I thought we are on the right track. But seemed like what he said is the truth. Let him be in our custody first, we need to ensure his safety if someone is trying to frame him. I will come back soon, after my shower. Get in touch with Hae for the latest murder details". 

"Got it, Sir" Hyukjae, Kyuhyun's one-down, replied and hang up. Detectives Hyukjae and Donghae are his best right-hand men in his team. They are his one-down, and they in turn has 2 other team members reporting to them. Hyukjae has Yesung and Henry, while Donghae has Ryeowook and KiBum. Kyuhyun's team are using codename ELF, where Kyuhyun is ELF1, Hyukjae's team is ELF2 and Donghae's team is ELF3. ELF stands for Efficient, Loyalty and Fast. 

Kyuhyun showered, changed and was out of his house in 15 minutes. Once he reached the police headquarters, Hyukjae gave him the documents from the Superintendent which gave the clearance to release the suspect. Kyuhyun walked to the room where they held the suspect to release him. 

"Hi Mr Lee. You are free to go. Very sorry we held you for the whole night. This is the document for your clearance, if you could just sign here" Kyuhyun pointed to the section for Mr Lee to sign. "And I will you back to your house to ensure your safety" Kyuhyun added. 

"There you go" Sungmin returned back the document after he has signed. "And thank you for the offer to send me back. I am so tired I don't think I have the energy to take other transport. Will be ok if we eat something? I'm sleepy but so hungry" Sungmin said, yawning. 

Lee Sungmin is a novelist and has a novel series with the title "Murder, He Wrote". Strangely, the serial murders that is happening now were exactly the same scenario as his book. When Sungmin was held in police custody, he kept telling Kyuhyun that the murderer must be his fan who is fanatic about his book, because the murder scene depicts exactly the same details as his novel. Sungmin was not angry at the police and at Kyuhyun at all for initially suspecting him, he was glad to help whichever he can. 

"Inspector Cho, remember i told you that I received a letter from a fan, asking me when is my next book is going to be published? Do you want to take a look at that letter? It could be the serial murderer who make use of my novel to gain ideas on how and who to kill next" Sungmin suggested. 

"I was thinking of that, but maybe it's really from your fan. But if you don't mind, yes I would like to take a look". 

"Sure, maybe when we reached my apartment, you follow me in? I can pass you the letter".  

"Ok thank you, Mr Lee, my car is this way. Maybe we dropped by somewhere to get some food?"

"Sounds good. Yes I'm so hungry. Don't the police headquarters have a cafeteria for you staff to eat? We can just go there too, I'm really not choosy"

"Our headquarters are the lousiest! We only has snacks and bun machines. Normally we just order delivery if we couldn't go home due to urgent homicide cases" Kyuhyun opened his passenger door for Sungmin to get in. 

While driving, Kyuhyun were also very alert to constantly check whether any vehicles were following them. He has his loaded gun with him and protecting a police custody has always been his top priority. 

Kyuhyun stopped by a cafe which was away from the main street, called Don't Don, owed by a jovial person named Shin Donghee. Kyuhyun told Sungmin this cafe is nice and it has security surveillance cameras all around the cafe. He visited this cafe numerous time and knew the owner personally because he is a valuable informant. 

When their foods arrived, Kyuhyun talked a while with Mr Shin and they exchange a paper as though they were shaking hands. Kyuhyun then started eating and browse through his phone. He put the paper next to his phone and read the message. Then he looked up to Sungmin. Sungmin rise his browse silently asking what is it? 

Kyuhyun then folded the paper and slot it in his phone cover. 

"Inspector Cho, do you want to ask something? "

Without looking up, Kyuhyun said there were 2 guys on a table right side of Sungmin who kept looking at him. Either they were Sungmin's fans or they knew Sungmin, but they were suspicious nevertheless. Sungmin had swear again that he is not the murderer and it really must be a fanatic fan of his. 

When they reached Sungmin's condo, Kyuhyun surveyed the area whether they were being followed before entering the basement carpark. He escorted Sungmin to his unit and entered his apartment first to check whether it was safe. If Sungmin is not the murderer, that means the real murderer is all out to frame Sungmin. 

When it was safe to enter, Sungmin went straight to his room to retrieve the letter from a fan. He told Kyuhyun that he had used leather gloves when he took it from his letter box as the weather was cold, and as the letter looked suspicious, he had use a disposable gloves to open the letter, and kept the letter in a plastic folder. He passed Kyuhyun a disposable gloves too so that any fingerprints on the paper, could still be traced. 

Kyuhyun thanked him and would bring the letter for fingerprints verification and will update Sungmin. 

Just then, a small rock smashed Sungmin's side window, which made Kyuhyun quickly dive and protect Sungmin.