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.

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.

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.

A girl with a secret. Longbill Beach, 1982. Emily Vaughn gets ready for the prom. For an athlete, who is smart, pretty and well-liked, this night that should be the highlight of her high school career. But Emily has a secret. And by the end of the evening, that secret will be silenced forever. Forty years later, Emily’s murder remains a mystery. Her tight-knit group of friends closed ranks; her respected, wealthy family retreated inwards; the small town moved on from her grisly attack. But all that’s about to change.

The debut psychological thriller that will forever change the way you look at other people's lives. Every day the same. Rachel takes the same commuter train every morning and night. Every day she rattles down the track, flashes past a stretch of cozy suburban homes, and stops at the signal that allows her to daily watch the same couple breakfasting on their deck. She’s even started to feel like she knows them. Jess and Jason, she calls them. Their life - as she sees it - is perfect. Not unlike the life she recently lost.

As dusk approaches a small Dublin suburb in the summer of 1984, mothers begin to call their children home. But on this warm evening, three children do not return from the dark and silent woods. When the police arrive, they find only one of the children gripping a tree trunk in terror, wearing blood-filled sneakers, and unable to recall a single detail of the previous hours. Twenty years later, the found boy, Rob Ryan, is a detective on the Dublin Murder Squad and keeps his past a secret.

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.

The old Victorian pier was a thing of beauty until it was allowed to decay. It was where the youth of Oldcliffe-on-Sea would go to hang out. It's also where 21-year-old Sophie Collier disappeared 18 years ago. Francesca Howe, known as Frankie, was Sophie's best friend, and even now she is haunted by the mystery of what happened to her. When Frankie gets a call from Sophie's brother, Daniel, informing her that human remains have been found washed up nearby, she immediately wonders if it could be Sophie.

Psychiatrist Dr. Gwen Moore is an expert on killers. She’s spent a decade treating California’s most depraved predators and unlocking their motives - predators much like the notorious Bloody Heart serial killer, whose latest teenage victim escaped and then identified local high school teacher Randall Thompson as his captor. The case against Thompson as the Bloody Heart Killer is damning - and closed, as far as Gwen and the media are concerned. If not for one new development.

Cassie thinks she has met the perfect man. Joel is sweet, handsome, romantic, and best of all, he’s crazy about Cassie. She thinks she’s found the guy she’ll spend the rest of her life with. Have children with. Grow old with. Yes, she knows about his perfect ex-girlfriend, Francesca. The beautiful, brilliant chef, beloved by all his friends. But she thinks Francesca is out of the picture. She thinks Francesca is gone for good. Think again, Cassie.

Naomi Shaw used to believe in magic. Twenty-two years ago, she and her two best friends, Cassidy and Olivia, spent the summer roaming the woods, imagining a world of ceremony and wonder. They called it the Goddess Game. The summer ended suddenly when Naomi was attacked. Miraculously, she survived her seventeen stab wounds and lived to identify the man who had hurt her. The girls’ testimony put away a serial killer, wanted for murdering six women. They were heroes.

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.

It's June in Montreal, and Dr. Temperance Brennan, who has left a shaky marriage back home in North Carolina to take on the challenging assignment of Director of Forensic Anthropology for the province of Quebec, looks forward to a relaxing weekend in beautiful Quebec City. First, though, she must stop at a newly uncovered burial site in the heart of the city. The remains are probably old and only of archeological interest, but Tempe must make sure they're not a case for the police. One look at the decomposed and decapitated corpse, stored neatly in plastic bags, tells her she'll spend the weekend in the crime lab.

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.