Oliver encounters a mysterious woman, Helena Bertinelli, daughter of mob boss Frank Bertinelli, who he can finally be himself with, but he soon comes to realize she's hiding dangerous secrets of her own. Helena is on her own personal mission of vengeance and Oliver is caught in the middle. Meanwhile, Tommy is blindsided by an unfortunate turn of events and turns to Laurel for support.

As Oliver and Helena grow closer, Oliver trains her to be his ally, complete with showing her how to use a crossbow. Diggle disapproves of Oliver sharing his secret with Helena as he's not sure she can be trusted, but Oliver refuses to listen to his concerns. Helena's quest for revenge proves to be too strong for Oliver to handle after she kills the head of the Triad and all hell breaks loose.

The Huntress returns and takes hostages at the courthouse when her father is arrested. Laurel is among those taken, which prompts her sister, the Canary, to battle the Huntress in an epic confrontation. Meanwhile, Roy tries to keep Thea safe, but he doesn't like the way he is forced to do it.