Season 321 :03x01 - The Weight of This CombinationApr/18/2015Season 3 begins with Sarah pursuing the missing Helena who is being held in a faraway compound. Sarah uses her wiles and acting chops to deter a Topside investigator who threatens the Leda sisters' lives. Meanwhile, Cosima appears to be rebounding from her illness, while Alison and Donnie face newfound financial woes. When the menace of Castor rears its head once more, Sarah and her entire family must come together to survive.

22 :03x02 - Transitory Sacrifices of CrisisApr/25/2015Castor pursues the Leda clones for original tissue samples. Helena, who is pregnant and imprisoned, is examined by a mysterious new villain.

23 :03x03 - Formalized, Complex, and CostlyMay/02/2015Leda and Castor are both on the hunt for original clone DNA. Mark and Gracie still on the lam pursue new leads to find the samples that might set them free, while Art and Sarah reunite to track them down. Cosima and Scott attempt to learn more about Castor�s biology. 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.

24 :03x04 - Newer Elements of Our DefenseMay/09/2015Sarah must step in to help when Mark is taken down in a Prolethean shoot-out. As Sarah collects intel putting her on the trail of the original Castor DNA, a familiar foe is not far behind. Helena continues to toil in a faraway military compound but it is ultimately Sarah�s fate that will hang in the balance as she tries to save her sister. Gracie is cast out from the Prolethean fold. Alison and Donnie come face-to-face with an unhappy drug lord.

25 :03x05 - Scarred by Many Past FrustrationsMay/16/2015Helena and Sarah are reunited at the Castor camp after Sarah is captured. 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 Amish' under the care of Mrs. S and an unwilling Felix. Cosima falls hard for an internet date.

26 :03x06 - Certain Agony of the BattlefieldMay/23/2015Paul finds the ugly truth behind the Castor Boys� logbooks of names which pushes him into action. Felix is desperate for information on Sarah�s whereabouts so he pressures 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 convince Jason Kellerman that her unique business plan will work.

27 :03x07 - Community of Dreadful Fear and HateMay/30/2015Alison must secure a store front in order to take their drug business to the �next level�. But Allison's her mother, Connie, proves to be a major hindrance. Felix helps Allison on her campaign for school trustee. Cosima, facing familiar health issues she thought she was over, calls on Alison for a favor. But it's Cosima who ends up doing a favor what with Alison trying to save Donnie from a heartless drug lord. Unassuming Scott gets closer to the greatest discovery of all when he sits down with Rachel to work on the secret key to decipher Ethan�s book, The Island of Dr Moreau.

28 :03x08 - Ruthless in Purpose, and Insidious in MethodJun/06/2015Rachel agrees to decipher the secret code in Ethan's book but Sarah and the clone club will have to find a secret way out of Dyad for Rachel. Helena and Gracie work with Alison and Donnie at Bubbles. Donnie confronts Allison about Jason�s kiss and devises a plan to set Jason straight. Dr. Coady and Benchman scheme to track down the Castor Original. Rudy drops in on DYAD for a much needed asset. A new clone enters the picture.

29 :03x09 - Insolvent Phantom of TomorrowJun/13/2015Sarah, Felix and Mrs. S travel to London in hopes of finding the Castor Original but their enemies are not far behind. Donnie tries to save the family business when Pouchy absconds but it's Helena who manages to secure a "full refund". Cosmia is suspicious of Shay so Delphine attends to matters on her own. Everything will change when Leda finds what they've been looking for.

30 :03x10 - History Yet to Be WrittenJun/20/2015Castor and Topside force Sarah to make uncomfortable alliances. Donnie gives Helena an unexpected "gift" and the results of Alison�s candidacy finally come in. As team Leda takes a moment to breathe, change is in the works and a life hangs in the balance.