Orphan Black - Season 4

After evading a Neolution attack in Iceland, Sarah returns home to track down an elusive new ally. She follows breadcrumbs and uncovers the next facet of Neolution's agenda - implanting dangerous technological devices in humans. However, those she left behind are wary about her return, not wanting to relinquish their semblance of normality. As Cosima struggles with Delphine's disappearance, Alison and Donnie host a pregnant and ever-hungry Helena. Meanwhile Felix, feeling like an outsider, embarks on his own journey of self-discovery.

As Sarah reels from the shocking discovery of Neolution's biotech, she's desperate to find answers. Always impulsive, she follows a lead into a harrowing encounter that requires the help of a reluctant new player. Eager to assist, Mrs. S strikes an alliance with an old nemesis. Rachel receives a visit from her keeper and takes a fraught step forward towards recovery. Meanwhile, Helena is mistaken for "Mrs. Hendrix" when she answers a visit from suspicious visitors.

Sarah realizes her goals have aligned with her once enemy and forms a precarious alliance in hopes of getting to the head of Neolution. Meanwhile, on her end, Alison dispatches Felix and Donnie to infiltrate a Neolution fertility clinic that Beth investigated. Back at the lab, Cosima and Scott receive a revolting delivery from Alison. As Rachel grows closer to Charlotte, Susan Duncan leaves a devastating decision in her hands.

Sarah's day off to reconnect with Kira quickly turns into a sleuthing mission aimed squarely at discrediting Felix's new ties. Cosima steps up with Donnie to further investigate the Neolutionist fertility research center. While Donnie bumps into an all too familiar face, Cosima makes a shocking discovery that leads her into a dangerous encounter.

When Cosima admits doubts about finding a cure in time to save her life, Sarah makes a lone decision that exposes Kendall to those she's spent years hiding from. Meanwhile, Art and Felix team up to protect naïve clone, Krystal Godderitch, from herself.

Sarah regresses to old habits while struggling to cope with the consequences of her decisions - reconnecting with Beth on a dark night of the soul. Back at the lab, Cosima, haunted by vicious memories and news of Delphine, attempts a dangerous Hail Mary to find a cure. At the Hendrixes, Alison is more determined than ever to create normalcy for her kids. As she forges ahead with a birthday party, Donnie is caught in the Neolution crosshairs.

As Alison is terrified by Neolution threats made against Donnie, Sarah and Mrs. S question her loyalty to her sestras. While Sarah is distracted, Siobhan sneaks out to seek vengeance. Meanwhile, Cosima and Susan Duncan work together in a final attempt to discover a cure.

With Susan Duncan deposed, Sarah finds herself in the same position as Rachel - under the heel of a new HBIC - causing the archenemies to come together for the greater good. Cosima and Susan butt heads on the ethical implications of human experiments. Meanwhile, when the Hendrixes legal counsel, Adele, further investigates Donnie's case, she begins to suspect Felix is keeping deep secrets. Helena's arrival forces Felix to make a difficult decision.