L's dad was the famous detective, Dr. K. He was the best detective and the boss from the biggest detective company in Korea. L ran away from home when he was 16 because of his mother's death. He came to Busan by himself and became the famous young detective genius, L. But one day he got a call from his brother that his dad got murdered. The only thing that his dad left for him was his diary containing an unsolved case. Will he

The days of Falcon and the Diamons are over. Bae Jangmi got arrested and everyone is living their own lives. This detective L special side story is about the hidden stories behind Shin and Bae Jangmi Read Detective L and the secret behind the diary first if you haven't read it yet.