Free Evil at Heart by Chelsea Cain

Just a flash. She jerked the flashlight beam to the left just in time to see the back end of a rat skitter past a beer can.
               
                She made it halfway up the stairs in two steps. Not that she was scared of rats, she told herself—she was just suddenly in a very big hurry. The stairs led up to the kitchen. With all the windows covered, the first floor was even darker than the basement. She knew it was the kitchen only because of the cracked speckled linoleum on the floor. There were footprints in the dust on the floor, seemingly dozens, in random patterns, like there’d been a scuffle there, or a square dance.
               
                There were no appliances in the kitchen anymore, just empty wooden cupboards and fittings for gas pipes sticking out of the wall where an oven used to be. The sink was filled with more beer cans. There were no dead bodies.
               
                Susan squeezed the flashlight in her armpit, and got her notebook and pen out of her purse. She had to hold the flashlight under her chin to see what she was writing, but she managed to take a few notes. Footprints. Miller High Life cans. Really fucking spooky.Also, rat.
               
                She put the notebook and pen away, took the flashlight back in her hand, and followed the beam out of the kitchen into a dark hallway and toward the front of the house until she came to a bedsheet that blocked the entrance to the next room. The sheet had been nailed to the ceiling and hung to the floor like a makeshift door. Classy.
               
                Rat-borne illnesses killed almost thirteen thousand people a year.
               
                Susan heard another bus rumble by.
               
                She felt strangely calm now. Like she was watching herself in a movie.Like she was one of those girls who go into the spooky house alone while the audience hides their faces and screams at her not to do it. The house was empty. She had done it. She’d crawled through a fucking basement window. She’d battled a rat. It was practically heroic. She was going to dine out on this story for months.
               
                She just had to find her way out.
               
                Her flashlight beam threw a yellow circle on the sheet. “Hello?” she said. She listened, not expecting to hear anything, and then, slowly, pulled the sheet curtain to the side and walked into the room.
               
                The first thing she noticed was that it was clean. Not regular clean. Weird clean.Crazy clean. Her flashlight beam reflected off the scrubbed hardwood floors. The walls and ceiling were a freshly painted white. It smelled different. Like disinfectant. Like a hospital.
               
                Susan’s stomach somersaulted as she panned her flashlight around. No furniture. No dust. No cobwebs. Whoever had been squatting there had been a real OCD case. Her flashlight swung past the open pocket door to another room, and stopped. Someone had hung clear plastic sheeting between the two rooms. Visqueen. Her mother kept a sheet of it over the compost pile.
               
                She forgot what she was doing. She forgot that she was looking for a way out. She moved toward the plastic, flashlight in hand, but it was so thick that the beam of light couldn’t penetrate it enough to see the other side. She tried to pull it aside but it was nailed up more securely than the sheet in the hall, and she had to duck down and squeeze through below where it was fastened.
               
                She turned, straightened up, and lifted her flashlight to look around.
               
                Something was in