A haunted cathedral. A possessed priest. Sarah Pearson and David Ritter confront a terrifying enemy, one with a plan that dates back centuries.

When Margaret and her husband Hal bought the large Victorian house on Hawthorn Street—for sale at a surprisingly reasonable price—they couldn’t believe they finally had a home of their own. Then they discovered the hauntings. Every September, the walls drip blood. The ghosts of former inhabitants appear, and all of them are terrified of something that lurks in the basement. Most people would flee. Margaret is not most people. Margaret is staying.

Episode Thirteen takes them to every ghost hunter's holy grail: the Paranormal Research Foundation. This brooding, derelict mansion holds secrets and clues about bizarre experiments that took place there in the 1970s. It's also famously haunted, and the team hopes their scientific techniques and high tech gear will prove it. But as the house begins to reveal itself to them, proof of an afterlife might not be everything Matt dreamed of.

Sisters Sarah and Chloe inherit a house they could never have previously dreamed of owning. It seems too good to be true. Shortly after they move in, however, the siblings start to notice strange things: horrible smells, sudden drops in temperature, as well as unexplainable sounds and feelings of being watched.

In the summer of 1994, psychologist Daniel Hill buys a rustic farmhouse nestled in the rolling hills of West Virginia. Along with his wife and teenage daughter, the family uproots their lives in Ohio and moves south. They are initially seduced by the natural beauty of the country setting. That soon changes when they discover a hidden room in the basement with a well, boarded shut and adorned with crucifixes. Local legends about the previous owner being an exorcist come to light, but by then, all Hell has broken loose.