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.
Jay agrees to sub in on Cam’s bowling team, not knowing it’s an all-gay league. Phil and Clair have an unexpectedly nice time with their neighbors. Gloria and Mitch agree to go out with Haley.
Ra’s al Ghul finally makes Oliver an offer he can’t refuse. The team joins Oliver on his journey to Nanda Parbat where a heartbroken Felicity decides to take matters into her own hands.
When Frankie’s uncle contacts her dad hoping to make amends, Frankie and Mike are caught in the middle of their feud; Sue turns to Axl for advice when she is sent to detention for the first time.
A dangerous new alliance is formed as Coulson and Hunter turn to the last person anyone would expect – Grant Ward! As the war between S.H.I.E.L.D. factions continues, Skye and Lincoln will find themselves drawn into this conflict.
Joe and Cisco head to Starling City to continue their investigation of Dr. Wells. While in town, the duo enlists the help of Captain Lance, and Cisco meets the Black Canary, who asks him for a favor. Meanwhile, back in Central City, Barry races to catch a meta-human named Hannibal Bates who can transform himself into every person he touches – which includes Eddie, Iris, Caitlin and even The Flash.
A former boyfriend lures Britta into joining Honda’s guerilla marketing campaign. Jeff looks to get Elroy to like him.
A mysterious recurring dream drives Castle and Beckett to seek answers about the two-month period when he went missing. But their search for the truth has deadly consequences.
Arya arrives in Braavos; Podrick and Brienne run into trouble on the road; Cersei fears for her daughter’s safety in Dorne as Ellaria Sand seeks revenge for Oberyn’s death. Stannis tempts Jon; an adviser tempts Daenerys.
Sarah pursues the missing Helena who is held in a faraway compound. Sarah must use 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. But when the menace of Castor rears its head once more, Sarah and her entire family must come together to survive.