Connor Allen was trapped in the basement of Adler department store. He had been there working, sweeping and waxing the floors of the four-story building. He worked there every Saturday night, after the store had closed. It was a job that he had taken to earn money for college. His only company during that graveyard shift was an aged security guard.

Neither were prepared for what happened that night. Four men broke into the store. They intended to rob it. They didn't intend to leave any witnesses. Bill Collins, the store security guard, was murdered trying to prevent the robbery.

A cat and mouse game ensued as Connor moved from one hiding place to another it the dark, cold basement of Adler. His only hope for escaping the killers was reaching the fourth floor of the department store. From there, he could escape to the roof and down the fire escape to the street below. But the only way to the fourth floor was up a hidden stairway. That stairway had not been used in years. It was sealed off after the fourth floor closed ten-years before.

A murder had taken place on that floor. The floor was never re-opened after the murder. But, since it's closure, voices, laughter, and gunshots had been heard coming from that floor. It was rumored that ghosts lived there. But Connor had no choice. That was the only exist available to him.

On the fourth floor, he discovered many secrets about the murders, about the Adler family, and about the history of that department store. He would discover that the strangers that were hunting him weren't the only threats to his life. Through the insane mind of a stranger living on the fourth floor, he discovered the secrets of the murders and the reason that the strangers would never stop until he was dead.

But did the robbery and murders actually occur? Or were they the imagination of a sick mind? The final chapter takes place in a psychiatric hospital, where nothing is exactly how it seems.