The building

You are a real estate agent. Full of debts to pay, and no matter how hard you try, you barely have any customers, and the situation is desperate. One day, late in the afternoon, someone calls you to evaluate the price of a building that needs to be sold urgently. You are in a desperate situation, and you quickly accept it, because any work in this moment of despair is welcome. As soon as you arrive at the indicated address, you see a building that is in the middle of nowhere. All dilapidated, and falling apart, your instinct tells you not to enter, but your circumstances do not allow you to retreat. You enter the building that seems to have been abandoned for a long time, it is dirty and damp, and you feel that there is something wrong in the building. Suddenly a figure passes quickly from one room to another. You turn around to leave the building, scared. The door is locked...