Sarah, Felix, and Mrs. S are in London to track down the Castor Original, but their enemies are not far behind.

When Rachel makes a promise to Sarah, it comes with a hefty price. Meanwhile, Helena and Gracie work with the Hendrixes, and Donnie takes Kellerman to task. Over at Castor, Coady and Benchman scheme to track down the Castor Original, and Rudy descends on DYAD for a much needed asset.

Alison must secure a store front in order to take her and Donnie’s business to the “next level”. But things don’t go according to plan when her mother, Connie, proves to be a major hindrance. Cosima is facing familiar health issues and calls upon beleaguered Alison for a favor. But with Alison working to save an imperiled Donnie from the merciless hands of a drug lord, it’s Cosima who ends up doing a favor. An unassuming Scott gets closer to the greatest discovery of all, when he sits down with beleaguered clone Rachel.

Paul digs and finds the ugly truth behind the Castor Boys’ logbooks of names, pushing him into action. Meanwhile, Felix is desperate for info on Sarah’s whereabouts, and presses the still-ailing Rachel for any shred of a lead. In order for Donnie and Alison to take their money-making endeavor to the “next level” she must introduce Jason Kellerman to her unique business plan.

Helena and Sarah are reunited at the Castor camp. As Sarah suffers testing, Paul appears to chide her; but his allegiances are beginning to strain. While the Leda family worries about Sarah’s absence, Gracie ‘breaks loose’ under the care of Mrs. S and an unwilling Felix. Cosima falls hard for an internet date, Shay.

Mark is taken down in a Prolethean shoot-out and Sarah must step in to help. But as Sarah gathers intel that puts her on the trail of the original Castor DNA, a familiar foe is not far behind. While Helena continues to toil in a faraway military compound, it is ultimately Sarah’s fate that will hang in the balance as she tries to save her sister. Meanwhile, Gracie is cast out from the Prolethean fold, and Alison and Donnie come face-to-face with unhappy drug lord, Jason Kellerman.

Leda and Castor are both on the hunt for original clone DNA. On-the-lam, Mark and Gracie pursue new leads to find the samples that might set them free, while Art and Sarah reunite to track them down. Meanwhile, Cosima and Scott try to learn more about Castor’s biology and Alison’s new money-making venture is going gangbusters. A shocking revelation about the Castor-Leda connection leaves the sisters reeling, just before Sarah witnesses a deadly Prolethean-Castor face-off.

Castor pursues the Leda clones for original tissue samples. Helena, who is pregnant and imprisoned, is examined by a mysterious new villain. The Castor boys are also out to play, toying with a frightened young woman, Patty, in a sexy switcheroo that ultimately sets Sarah – and Art – hot on the Castor trail. But it’s not all fun and games for the Castor boys, as Sarah gleans they may have a mysterious defect that puts their lives in peril.

When the menace of Castor rears its head once more, Sarah and her entire family must come together to survive.

The war with Dyad is all but lost when Rachel’s latest ploy forces a broken Sarah to concede. The Clone Club springs into action, uniting in a reckless gambit to save Sarah. As they fight to gain their freedom, Sarah encounters a new ally and uncovers a terrifying new dimension to the conspiracy.

Cosima takes a turn for the worse, forcing Sarah to take desperate action which results in tragic consequences for those she loves. The Proletheans set their ultimate plan in motion, while Alison and Donnie tangle with the law.

A new player in the clone conspiracy turns up at Felix’s door, sending him into crisis mode. With Cosima running out of options, Sarah struggles with the decision to surrender a crucial piece of leverage and make a deal with Dyad.

When a rehab confidante betrays Alison and threatens to expose the truth about Aynsley’s death, she goes into free fall on the eve of Family Day. With Donnie and the kids set to visit, it’s all clones on deck to contain the fallout.

Sarah joins forces with an unlikely and untrustworthy ally, following a trail of clues that she hopes will lead her to the origins of the clone experiment. Cosima and Delphine make a discovery that could prove to be the key to treating her illness. Alison finds herself in unsavory company at rehab.

Rachel goes on the warpath, lashing out at Sarah’s nearest and dearest. While she tries to keep her loved ones safe, an unexpected visitor threatens to derail Sarah’s plans.

Sarah comes home looking for answers, and with the help of Cosima, they begin digging into the origins of the clone experiment. The hunt for answers takes her right into the belly of the beast, but getting out could cost her more than she knows.

After hitting the road with Felix, Sarah is forced to turn to a ghost from her past – an old flame named Cal Morrison. When their brief respite is brutally shattered, Sarah realizes that no matter how far she runs, it will never be far enough.

While Alison struggles with Aynsley’s death and Cosima grapples with the worsening symptoms of her mysterious sickness, Sarah enlists Art’s help to find Kira and is shocked when she learns where the trail leads.

Sarah is out of options, on the run, and pursued by deadly adversaries. Desperate to find her daughter Kira, Sarah suspects ruthless pro-clone Rachel is behind her daughter’s disappearance and sparks an all out war against her. Alison and Donnie attend the funeral of her fallen friend, Aynsley, causing Alison to sink into guilt and despair. Cosima is faced with a perplexing decision that may have dire consequences.

Sarah’s last chance to bring her nemesis back to sanity slips away as Art intervenes to get answers of his own. Meanwhile, the Orphans must decide whether to make peace with their creators, as Sarah is forced into a deadly confrontation with their enemy.

After Kira’s life is threatened, Sarah is on the warpath, but Dr. Leekie makes her think twice about her plans for revenge. Meanwhile, Cosima faces the truth about Delphine, forcing her to choose sides. Now, it’s up to Sarah to decide the killer’s fate, but the truth about where Sarah came from changes everything.

Sarah’s actions pit the Orphans against each other as she tries to plan her next move. As Paul tries desperately to cover up Sarah’s existence, Alison takes vengeance on her suspected monitor, which could cost her everything she holds dear.

With Paul missing, Sarah is forced to confront the conspiracy head on. But when Paul learns Sarah has kept essential information from him, the fragile trust between them threatens to shatter. Meanwhile, Cosima grows closer to Delphine and the dangerously fascinating Dr. Leekie.

Sarah’s hunt for answers is interrupted by a trip to the suburbs. Alison’s paranoia has boiled over, putting all the Orphans at risk. But when Sarah, Alison and Beth’s worlds dangerously collide, Sarah must decide who to trust with her secret.

When terrifying evidence suggests the Orphans are part of a sinister ongoing experiment, Sarah’s suspicions turn to Paul, Beth’s boyfriend. But her probing inadvertently triggers Paul’s own investigation, bringing him dangerously close to the truth. Meanwhile, paranoid Alison piles on a whole new level of complication.

Sarah realizes that the Orphans’ survival is going to take more than police work. But tracking the killer threatens Sarah’s long awaited reunion with her daughter, Kira. As Sarah gets closer to the killer, the killer gets closer to the truth – the ensuing showdown threatens to expose her ruse as a cop.

Rocked by the revelation that she and her fellow “Orphans” are clones, Sarah just wants to get her hands on the money and skip town. But Sarah’s fake detective ruse stretches thin when the cops find the body she buried and assign “Beth” to the case. As Sarah closes in on the killer, the hunter becomes the hunted.

With a body in her car and nowhere to turn, Sarah is forced to continue her con and earn “Beth” a second chance on the force. But with a killer on her tail, her only hope of finding answers lies with another apparent ‘identical,’ Alison.

Sarah, a streetwise hustler on the run from a lifetime of bad decisions, witnesses the suicide of a stranger who looks just like her. Sarah assumes her identity, hoping that cleaning out the dead woman’s bank account will solve all of her problems. Instead, the street smart chameleon is thrust headlong into a kaleidoscopic mystery. After taking on the new identity, Sarah quickly finds herself caught in the middle of a deadly conspiracy and must race to find answers.

Wayne struggles to hold on to his memories, and his grip on reality, as the truth behind the Purcell case is finally revealed.

Following up on new leads, Wayne and Roland track down a man who left the police force in the midst of the Purcell investigation. Meanwhile, Amelia visits Lucy Purcell’s best friend in hopes of gaining insights into the whereabouts of the mysterious one-eyed man.

Wayne and Roland revisit discrepancies in the Purcell case that were hidden or forgotten over the years. Among those being reevaluated is Tom Purcell, as well as Lucy Purcell’s cousin, Dan O’Brien. The glitter of Amelia’s book release is tarnished by a voice from the past.

Wayne finds himself in a no-win situation as new clues emerge in the Purcell case. Roland wrestles with how to keep evidence secure as lawyers demand a new investigation. Amelia finds her relationship with Wayne imperiled by her writing aspirations and his jealousy.

Hays and West see a possible connection between the local church and the Purcell crimes. As the detectives search for one suspect and round up another for interrogation, Woodard is targeted by a vigilante group.

Hays recalls his early romance with Amelia, as well as cracks in their relationship that surfaced after they married and had children. Ten years after the Purcell crimes, new evidence emerges, giving him a second chance to vindicate himself and the investigation.

Hays looks back at the aftermath of the 1980 Purcell case in West Finger, Arkansas, including possible evidence left behind at the Devil’s Den. As attention focuses on two conspicuous suspects–Brett Woodard, a solitary vet and trash collector, and Ted LaGrange, an ex-con with a penchant for children–the parents of the missing kids, Tom and Lucy Purcell, receive a cryptic note.

The disappearance of a young Arkansas boy and his sister in 1980 triggers vivid memories and enduring questions for retired detective Wayne Hays, who worked the case 35 years before with partner Roland West. What started as a routine case becomes a long journey to dissect and make sense of the crime.

Frank, Ray and Ani weigh their options as Caspere’s killer and the scope of corruption is revealed.

Ray, Ani and Paul take precautionary measures to elude detection and untangle a dark mystery; Frank deals with the fallout of his betrayal.

Desperate to locate a missing woman with intel about Caspere, Frank meets with Mexican drug dealers; Ani infiltrates an exclusive inner circle, with Ray and Paul keeping close tabs.