When Detective Lauren Medina sees the calling card at a murder scene in Chicago's Humboldt Park neighborhood, she knows the Pied Piper has returned. When another teenager is brutally murdered at the same lagoon where her sister's body was found floating years before, she is certain that the Pied Piper is not just back, he's looking for payment he's owed from her. Lauren's torn between protecting the city she has sworn to keep safe, and keeping a promise she made long ago with her sister's murderer. 

Many Indigenous people believe that one should never whistle at night. This belief takes many forms: for instance, Native Hawaiians believe it summons the Hukai’po, the spirits of ancient warriors, and Native Mexicans say it calls Lechuza, a witch that can transform into an owl. But what all these legends hold in common is the certainty that whistling at night can cause evil spirits to appear—and even follow you home.

This trip is going to be Dylan’s big break. Her geologist friend Clay has discovered an untouched cliff face in the Kentucky wilderness, and she is going to be the first person to climb it. Together with Clay, his research assistant Sylvia, and Dylan’s boyfriend Luke, Dylan is going to document her achievement on Instagram and finally cement her place as the next rising star in rock climbing. Seven months later, three bodies are discovered in the trees just off the highway. All are in various states of decay.

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.