Criminal psychologist Audrey Harte is returning home after seven years. Less than 24 hours later, her best friend is murdered. Now, Audrey is both the prime suspect and the only person who can solve the case...It Takes One is the opening to a thriller series where a criminal psychologist uses her own dark past to help law enforcement catch dangerous killers.

Eighteen years ago, FBI Agent Rachel Ward's mirror twin, Hannah, was taken by the Gemini killer, a serial killer who delights in sending photos of his victims to their twins. Rachel assumes her sister has been dead for years, but she's never stopped hunting the monster who took her. Now, another twin has been taken, and when the case reopens, Rachel is assigned as an agent. But her relentless hunt for the killer may drive her to her breaking point.

Tracy Crosswhite has spent 20 years questioning the facts surrounding her sister Sarah’s disappearance and the murder trial that followed. She doesn’t believe that Edmund House - a convicted rapist and the man condemned for Sarah’s murder - is the guilty party. Motivated by the opportunity to obtain real justice, Tracy became a homicide detective with the Seattle PD and dedicated her life to tracking down killers.

In the remote forests of Stillwater, Minnesota, you can scream for days and no one will hear you. So when the bodies of two 15-year-old girls are discovered frozen in the snow, Special Agent Nikki Hunt is sure the killer is local: Someone knew where to hide the girls and thought they would never be found. Though Nikki hasn’t been home in 20 years, she knows she must take over the case.

Alice and Seth are a perfect love story: the handsome doctor and his beautiful fiancée. They’re wealthy, well liked and made for each other—the envy of all their friends. Alice can’t wait for the day of their dream wedding. But when she arrives at the altar, she doesn’t recognise the man waiting to marry her. When this stranger insists he’s Seth, her husband-to-be, the entire congregation seems to agree. Even her parents try to persuade Alice to go through with the wedding.

Lieutenant Abby Mullen is no stranger to crisis. As the hostage negotiation instructor for the NYPD, she deals with worst-case scenarios every day. Nothing fazes her anymore. That all changes when she gets a call from Eden Fletcher, a fellow survivor of the infamous Wilcox cult. The two haven’t spoken since the night of a tragic, fiery massacre, when their paths diverged. But now Eden needs Abby’s help: someone has kidnapped her son and is demanding a $5 million ransom. As Abby throws herself into the case, she can’t help but wonder why the kidnapper has targeted Eden.

Escaping from a madman should have been the end of her nightmare. Instead it was only the beginning...Lizzy Gardner was just seventeen when she was kidnapped by the psychopath known as Spiderman, a serial killer terrorizing her California hometown. Imprisoned and tormented for months, Lizzy narrowly escaped with her life and Spiderman vanished without a trace. But if she thought he would forget her, she was dead wrong.

Three Chicago women have been found strangled, embalmed, and posed as if still alive. Doubting the findings of the local PD’s profiler, the FBI calls on forensic psychologist Zoe Bentley to investigate. Zoe quickly gets off on the wrong foot with her new partner, Special Agent Tatum Gray. Zoe’s a hunter, intense and focused; Tatum’s a smug maverick with little respect for the rules.

It was supposed to be the perfect reunion: six university friends together again after twenty years. Host Ali finally has the life she always wanted, a career she can be proud of and a wonderful family with her college boyfriend, now husband. But that night her best friend makes an accusation so shocking that nothing will ever be the same again.

Daughter of a cold, controlling mother and an anonymous donor, studious, obedient Elizabeth Fitch finally let loose one night, drinking too much at a nightclub and allowing a strange man’s seductive Russian accent to lure her to a house on Lake Shore Drive. Twelve years later, the woman now known as Abigail Lowery lives alone on the outskirts of a small town in the Ozarks.

Charley sees dead people. That's right, she sees dead people. And it's her job to convince them to "go into the light." But when these very dead people have died under less than ideal circumstances (i.e., murder), sometimes they want Charley to bring the bad guys to justice. Complicating matters are the intensely hot dreams she's been having about an Entity who has been following her all her life...and it turns out he might not be dead after all. In fact, he might be something else entirely.

Three children, running in the woods behind their school, stumble upon a partially buried female body, eyes and mouth glued shut. Close behind the children is their teacher, Anne Navarre, shocked by this discovery and heartbroken as she witnesses the end of their innocence. What she doesn't yet realize is that this will mark the end of innocence for an entire community, as the ties that bind families and friends are tested by secrets uncovered in the wake of a serial killer's escalating activity.

When she was sixteen years old, Angela Wong—one of the most popular girls in school—disappeared without a trace. Nobody ever suspected that her best friend, Georgina Shaw, now an executive and rising star at her Seattle pharmaceutical company, was involved in any way. Certainly not Kaiser Brody, who was close with both girls back in high school.

On her first day of kindergarten, five-year-old Tinsley disappeared without a trace... Five agonizing years later, her divorced mother, Dani Callahan, is a private investigator. She and Quinn Sullivan, a promising young assistant determined to prove herself, are devoted to helping others find missing loved ones. And for Dani, finding Tinsley is still a never-ending obsession.

He performs his profane ceremony in a wooded Minneapolis park, anointing his victims, then setting the bodies ablaze. He has already claimed three lives, and he won't stop there. Only this time there is a witness. But she isn't talking. Enter Kate Conlan, former FBI agent turned victim/witness advocate. Not even she can tell if the reluctant witness is a potential victim or something more troubling still.