The Detective who deceive everyone

At 35 years old, Kang Shin has spent twenty years fascinated by crime.Working ordinary shifts at a supermarket, Shin lives a quiet life while spending his free time watching and studying criminal cases. He is fascinated by the way criminals think, how victims become trapped, and how the smallest clue can unravel an entire mystery.

To Shin, every crime is a puzzle.
But one night, after finishing his shift, something impossible happens.Shin receives a mysterious black book.He doesn't know where it came from. He doesn't know why only he can see it.

And before he can understand its purpose, his world changes.Shin suddenly travels back in time.When he opens his eyes, he is no longer thirty-five.

He is fifteen years old.
His younger body.
His old school.
His family from twenty years ago.

At first, Shin believes he has been given a second chance-a chance to change the mistakes he made in his life.
Then he opens the Black Book.
Inside is a case he already knows.
A case he remembers from the future.
A case that happened years after his original life began.

CASE FILE 001
VICTIM: LEE HA EUN
TIME REMAINING: 7 DAYS

Shin knows how this case is supposed to end.
He remembers the tragedy.
He remembers the mystery that surrounded it.
But this time, he has seven days to change the ending.

The problem?

The moment Shin interferes, the future begins to change.

Clues disappear. People behave differently. New suspects emerge. And cases that Shin remembers begin unfolding in ways he never expected.

With the mind of a 35-year-old man inside the body of a 15-year-old, Shin must use everything he knows about crime to stay ahead.
But the more he investigates, the more he realizes that someone else may know about the future too.

And if he wants to save Lee Ha Eun, Shin will have to lie, manipulate and deceive everyone around him.

Because this time, he isn't solving a crime.
He's rewriting the future