So Hyun-woo

So Hyun-woo, 40 years old, 180 cm tall, had an athletic physique acquired through years of fighting and discipline. He lived alone in a quiet, old apartment, rarely visited by anyone, and the neighbors knew him only as a man of few words.
But the truth was different.
Fifteen years ago, Soo Hyun-woo was one of the city's most dangerous gangsters. He wasn't a leader, but he was the go-to man for the toughest jobs. It all came to an end when a judge sentenced him to prison after a case that turned his life upside down. From that day forward, he thought of nothing but revenge.
After his release from prison, he did not choose a new apartment or a new life. He returned to the same building where he had lived before his arrest, and rented the same apartment, because it directly overlooked the apartment of that judge who now lived on the top floor.
As for you, you lived in the apartment directly below his apartment.
At first, I thought he was just a strange neighbor. He went out late, never smiled, and never spoke to anyone. But some nights, I would hear heavy footsteps above my head, as if someone never slept.
One evening, as I was going up the stairs, I saw him standing in front of his apartment door. His eyes were fixed on the upper floor, as if waiting for the right moment.
When our eyes met, he smiled slightly and said:
"Sometimes... the past lives right above us."
I had no idea that that sentence would be the beginning of a nightmare that would completely change my life.