Can an FBI Academy dropout catch a vicious serial killer? It’s been fifteen years since Vivian Delacroix unleashed her followers on the town of Cardinal Falls. The cult members killed anyone Vivian told them was a threat to their beliefs. Now, another killer takes young girls of nine or ten, all related to Vivian’s original victims. He drugs them, suffocates them, and painstakingly arranges them in ritualistic poses. The bodies give up no evidence to the killer’s identity. When Wren Delacroix finds the latest victim in the middle of giving a tour, she’s forced to admit to herself that she came back to her home town because of her perverse interest in the case. These dead girls, she can’t get them out of her head. Even though she dropped out of the FBI Academy and tried to flee from the dark parts of herself, she can’t run away. Before she knows what she’s doing, she’s spouting her fully formed profile of the killer to Detective Caius Reilly, head of the tri-state task force, and she’s begging him to let her help. She needs to solve this case and stop this killer. If only to prove to herself that she’s nothing like her mother Vivian.

There are two kinds of serial killers—organized and disorganized. This killer that Wren Delacroix is trying to make a profile for? He’s both. Or neither. Or… she doesn’t know what, but she can’t make heads or tails of his crime scenes. The killer leaves his teenage-girl victims where he killed them. Naked, dirty, and destroyed, they are tossed aside like nothing, and he runs. This is classic disorganized presentation. However, the killer has also cleaned up after himself, leaving behind no evidence whatsoever, and he’s posting videos on YouTube, claiming responsibility and taunting the authorities. That’s something an organized killer would do. As the bodies pile up, Wren’s profile is exactly nowhere. And then a man hurt by her mother Vivian, entangled with Wren’s own past, emerges from the woodwork, desperate and violent. Now Wren has more pressing concerns than solving the case—like her own safety.

Copycat murders. Wren Delacroix doesn’t like them. They aren’t easy to profile, and this one is no exception. Whoever killed Oliver Campbell had intimate knowledge of a previous set of murders, and Wren can’t be sure who that could be. To make matters worse, Wren isn’t experiencing her typical eagerness to solve this case. Instead, thinking about it fills her with a crushing dread that seems to consume her. It’s as if she knows that once she solves it, things will never be the same. The trail of this killer sends Wren and Reilly tunneling into the past, to speak with Vivian Delacroix in prison, and eventually deep into the woods outside the compound, where they find a threat of blood and bone that spirals into chaos and violence. Soon, they are fighting for their very lives.

Months have passed since the events in the woods behind the compound, and with no new cases, the task force might be shut down. Wren Delacroix could leave town, but she lingers, even without any work. And then, there’s a report from a local hospital of a possible angel of death serial killer and the questionable deaths of a number of elderly patients. Wren and Reilly begin interviewing nurses. There’s a strong possibility this killer is female, and she may be nearly impossible to catch. But it seems that nothing in Cardinal Falls can escape the reach of the Fellowship or the shadow of the Crimson Ram. Soon, the two find themselves delving into the past, to the crime over a decade ago at “the tower,” where one madman claims serial killers were birthed in blood. And what was born in Wren herself back then? The deeper she digs, the more she fears that she’ll unearth unchecked violence within herself. After everything she’s been through lately, she’s… changed. Harder. Angrier. Outside, it’s frozen February. Inside, it’s hot turmoil.

When Wren Delacroix and Detective Caius Reilly investigate a new crime scene, they’re surprised to discover the killer has left a personal note, addressed directly to Reilly. As they unravel its cryptic message, they are led down a twisty road to reveal secrets about Reilly’s past and about his mother, a victim of the serial killer Mark Quentin Rhoads. This new killer means business. He’s vicious. He’s smart. He’s brutal. He’s playing a game with them. But only he knows the rules.

Wren and Reilly track the Quarantine Killer… On March 26, 2020, Sarah James hears a noise in her apartment. She lives alone, and she’s easily frightened. With the current state of the country, she’s harried. She goes through and checks each room, telling herself she’s overreacting. But she’s not alone. These will be her last moments on earth. With the entire state on lockdown, and no one leaving their homes for anything except essential activities, it is weeks before Sarah’s body is discovered, lots of time for the newly minted Quarantine Killer to have struck again. Wren Delacroix and Caius Reilly are working from home, going stir crazy without access to decent coffee. They’re happy enough to have a case to solve. Then the bodies start to pile up. Then the killer taunts them with his flagrant disregard for anything but his own twisted appetites. Now they have to do whatever they can to stop him.

Upon meeting Phineas Slater, Wren Delacroix can’t shake the feeling that there’s something off about him. The Cape Christopher homicide detective is an effusive fan of Wren’s and Reilly’s, and he tells them how excited he is to have them there in Virginia to help with the serial killer case which grips the sleepy coastal town. He’s charismatic and friendly. He’s eager to turn over all the information he has about the killer, who’s killing women, violating their bodies, and burying them along the highway. And yet, something about Slater isn’t right. Wren is convinced that he is, in fact, the killer they seek. But there is no evidence tying Slater to the murders, and he’s quite well-liked at the police department. It’s clear that he’s brought them there as part of some sort of twisted game, flaunting his crimes, flirting with capture, leaving bodies in his wake. All the while, they scramble to find some way to arrest him. They’ve never faced a killer so dangerously fascinated with them both. When they finally find the evidence they need, he’s waiting. Captured by this madman, now they will fight for their own lives.

It’s sticky and hot outside, and Wren Delacroix and Caius Reilly are bored. Ever since Hawk Marner’s appeal cast doubt on their ethics, it’s been crickets from police departments who want their help. With nothing to do but wait for the appeal, the two decide they could use a distraction. An FBI agent staying the facility that houses their new offices is trying to crack something in Northern California that could be a set of cult killings. They don’t really investigate cult killings.But it could be a serial killer.Or, it could be nothing at all.There are no bodies. There are just six couples who have all disappeared after frequenting an outreach program called Love Over Want. It’s not really their kind of thing, but… well, they are bored.

Poppy Morgan has been married four times, and none of her husbands survived their wedding nights. She’s a black widow killer, a woman who marries men and kills them one after another, and she’s in custody in New York state.Wren Delacroix gets a call to fly up there and interrogate Poppy. It seems that Poppy is holding a police officer captive in a secret location. She’s given him a slow-acting poison.The local police department wants Wren to get Poppy to give up the location of the officer in time for an antidote to be given. The clock is ticking.Reilly can’t come along, because he’s still recovering from a gunshot wound, so Wren’s flying solo on this.She can handle it.She can get everything she needs from Poppy Morgan.No problem.Wren’s not distracted by the results of that pregnancy test.At all.

Hawk Marner has been murdered. Wren Delacroix and Caius Reilly would be celebrating if it weren’t for the fact that they’re the main suspects for the crime. They weren’t together that night. Though both of them maintain their innocence, neither of them quite believes the other. It’s not as if they haven’t talked about killing him before. It’s not as if Hawk didn’t deserve it. But with the due date for the birth of their new daughter looming, they decide to give each other the benefit of the doubt and look for other suspects. Unofficially, of course. Their connections to Hawk mean they’re not allowed to investigate the case in any official capacity. It feels good to have a case again. But their lack of trust for each other erodes everything they are. And with the baby coming soon, they need to rely on each other now more than ever.