A flashback shows Thea the night when she left with Malcolm to become a better version of herself.
In the present, a new League of Assassins has risen as Athena has tracked down the heir of Ra's al Ghul. Nyssa is part of it as she is still alive after the explosion on Lian Yu.
Nyssa isn't down with this new League as she engages a fight. Back in the Arrow bunker, they are celebrating Thea's send-off.
As Thea and Roy take off, they are attacked by League members. But Nyssa stops them and tells Thea and Roy to come with her.
Thea says she is done with this, but Nyssa explains that like Ra's, Thea has to pay for the sins of Malcolm.
It is revealed that before Nyssa disbanded the League, Malcolm recruited a group known as the Thanatos Guild. Athena believes that Thea knows about some map and Nyssa needs Thea's help.
Despite being reluctant, Thea agrees to at least meet Athena. But after that, she is done.
When Team Arrow and Nyssa find the map, they are quickly joined by Athena and her group. As the two sides are both after the map, they begin to fight for it.