Barbara's past returns to haunt her as former nemesis Lady Shiva seeks revenge for the death of her little sister eight years prior. Several plot twists add to the story as we find out the Sandy (Lady Shiva) and Helena were BFFs in high school though they haven't seen each other in eight years. Meanwhile, Dinah learns a valuable lesson about the ethics and morality of superpower use when she goes over the line to get a boy to like her.
Sarah offers her unconditional surrender to Rachel and Dyad in order to free Kira, but the move prompts a number of unforeseen consequences. The four sisters unite for the first time, and we learn that Project Leda has split into two factions. Mrs. S trades Helena for Kira, and we've been introduced to not only male clones but also an 8 year old clone who acknowledges Sarah as her big sister.
The race to save Cosima's life takes a positive turn as Ethan Duncan arrives at Dyad and immediately begins to decode the genetic sequences with Scott's help. We see a new side to Donnie Hendrix, and Alison obviously likes what she sees after the two bury Aldous Leekie's body. But perhaps the biggest plot twist involves Kira and Rachel.
Two for the price of one isn't always a bargain, and while it seems the crime fighting trio have some help from a fellow meta-human, the story takes a quick turn. The Huntress/Reese relationship, if you can call it a relationship, hits a bump in the road when Lynn, the local DA, appears on the scene, and we find out that they dated, albeit briefly.
It's been awhile, but we're introduced to a new clone, and like Sarah in the beginning, has no idea of what he's a part. It gets a bit more complicated, but Ethan Duncan comes in from the cold to work at Dyad now that Aldous Leekie's been killed and the hope is that he can produce a cure for Cosima and potentially the others.
Dinah copes with the death of her mother, the Black Canary, while Barbara takes her relationship with Wade to the next level. Helena and Reese continue to spar, but both their lives are on the line as she puts herself out to help him bring in a gang that turns out to be working to fund Dr. Q's plot to take over New Gotham City. Will Helena eventually go too far in her thrill seeking?
Dr. Aldous Leekie is dead, killed by of all people, Donny Hendrix after Donny learns he's been lied to from the beginning. Now what? Ethan Duncan is in play and being guided by Mrs. S as they presumably bring the missing clone science to Cosima and Delphine so they can figure out why the clone are getting sick and find a cure. Is Kira the key? What will Donny and Paul do now? What will Rachel do now that she knows her father's alive and Leekie murdered her mother?