When FBI special agent Luke Kendrick discovers chilling evidence of dozens of victims at a crime scene in London, he recognizes the calling card of the notorious H. H. Holmes Society. Named for the eighteenth-century monster regarded as America’s first serial killer, the society is comprised of a twisted web of killers, working to carry out heinous murders in Holmes’s memory. And now the group’s been linked to a Scottish castle turned B and B—where guests check in but never check out.

When two hikers go missing within a series of daunting caves outside of Denver, Colorado, FDLE special agent Amy Larson and her partner, FBI special agent Hunter Forrest, have good reason to suspect foul play. The pair of hikers are only the latest to vanish after a rash of disappearances that’s left local law enforcement stumped. But in searching the dank caverns near the Arkansas River, the agents aren’t prepared for the horror they uncover: a muddy pit littered with corpses. Covered in bite marks. Made by human teeth.

A ritualistic murder on the side of a remote road brings in the Florida state police. Special Agent Amy Larson has never seen worse, and there are indications that this killing could be just the beginning. The crime draws the attention of the FBI in the form of Special Agent Hunter Forrest, a man with insider knowledge of how violent cults operate, and a man who might never be able to escape his own past.

Deep in the Florida Everglades, the body of a woman is discovered in pieces, presumably ravaged by an alligator. Upon closer inspection, it’s determined no animal could make such perfectly precise cuts. Only a blade could do that. Wielded by a human. Soon, dozens of oil drums emerge amid the river of grass. Each one packed to the brim with body parts.

A secret government unit is formed under the oversight of Adam Harrison, famed paranormal investigator. The case: In a historic mansion in New Orleans’ French Quarter, a senator’s wife falls to her death from a balcony. Most think she jumped, distraught over the loss of her young son. Some say she was pushed. And yet others believe she was beckoned by the ghostly spirits that inhabit the house - once the site of a serial killer’s grisly work.

When FDLE special agent Amy Larson discovers a small horse figurine amid the bloody aftermath of a gang massacre in the Everglades, she recognizes it immediately. The toy is the calling card of the apocalypse cult that Amy and her partner, FBI special agent Hunter Forrest, have been investigating, and it can only mean one thing: this wasn’t an isolated skirmish—it was the beginning of a war.

Margot needs a minute. She’s been working eighty-hour weeks as a newly minted partner at her law firm. She’s disconnected from her brother, the only family she has left. And she’s still not pregnant after years of trying. Stars Harbor Astrological Retreat promises rest, relaxation, and wisdom for Margot and her friends. With Instagram-worthy views and nightly astrology readings in an impeccably restored waterfront Victorian house, this getaway should be nothing but idyllic fun.

When a Category 5 hurricane is poised to hit their coastal Florida town, the Davies family takes refuge in their waterfront manse. Marlowe, Lee, and their teenage twins invite their close friends to wait out the storm in comfort and style. Uninvited are the three strangers who dock on the family’s shore right before the storm descends. Brothers Jason and Bo—and Bo’s girlfriend, Darcy—are a charming, helpful trio in need of a safe haven that the Davies are only too happy to provide. But as the storm outside grows more threatening, so does the tension in the house.

Everyone knows about Ashburn House. They whisper its old owner went mad, and restless ghosts still walk the halls. They say it's the dwelling place of something cruel and sinister. But when Adrienne, desperate and in need of a place to stay, inherits the crumbling old mansion, she only sees it as a lifeline...until darkness falls.

Detective Kara Quinn, on leave from the LAPD, is on an early morning jog in her hometown of Liberty Lake when she comes upon the body of a young nurse. The manner of death shows a pattern of highly controlled rage. Meanwhile in DC, FBI Special Agent Mathias Costa is staffing his newly minted Mobile Response Team. Word reaches Matt that the Liberty Lake murder fits the profile of the compulsive Triple Killer. It will be the first case for the MRT. This time, they have a chance to stop this zealous, if elusive, killer before he strikes again.