At the headquarters of 'Awtad' Investment Company, the Chief Financial Auditor was found murdered by blunt force trauma to the head inside the 'Secret Archive' in the basement. The archive is located at the end of a long, isolated hallway with no security cameras. The victim was investigating massive embezzlement cases and had received frequent threats. The body was discovered at exactly 1:00 PM when the maintenance manager opened the door. The case seems impossible because the main witness insists on having heard the victim alive and arguing with someone at a time when the perpetrator supposedly could not have accessed the crime scene.