Go home for the night

Melissa sighed again and decided to head home, she simply couldn't concentrate on the numners anymore. She was shutting the computer down when something caught her eye... The office door was shut; she could've sworn it was left open after the cleaning crew left. She shrugged it off to her being so tired and rose from her chair. Melissa walked around the desk to get her heels that she had kicked off, and as she walked she thought she heard a noise. Impossible, she thought, she was in the fifth floor of a 5 floor building, and the entire building was empty, she could see from her window that the parking lot was empty minus her own car. She must be hearing things, although it sounded like breathing. Ugh, must be her mind messing with her, she thought, and she bent down to grab her heels.

While slipping the high heels onto her feet, she heard a noise again and looked up...all she had time to do was gasp quickly...