In 1988, Philadelphia police officer Thomas "Locke" Lockhart, hungry to become a detective, begins tracking a serial killer whose crimes defy scientific explanation. When the killer mysteriously resurfaces nine years later, Locke's obsession with finding the truth threatens to destroy his career, his family, and possibly his sanity.
Stephanie, a dedicated mother and popular vlogger, befriends Emily, a mysterious upper-class woman whose son Nicky attends the same school as Miles, Stephanie's son. When Emily asks her to pick Nicky up from school and then disappears, Stephanie undertakes an investigation that will dive deep into Emily's cloudy past.
Eccentric Frank Carlyle ran a horror shop in small-town Steeple Falls, which takes pride in and profit from its Halloween traditions. Frank's widower grandson Richard grudgingly returns there from Boston with his own kids, bright Ian and bratty Claire, to settle the inheritance. Ian discovers great-grandpa's house is really haunted, and not just, as legend holds, by historic owner Zachariah Kull, who was burned on the stake.