Oliver learns that the DA has another witness against him–Roy Harper. Team Arrow set out to find Roy and learn if someone is coercing him to testify. Meanwhile, Black Siren passes herself off as Laurel and claims that she’s been in captivity for two years.
Thea discovers that Quentin has been hiding Black Siren, and Team Arrow comes to get her and find out where the missing money is. However, the Outsiders follow them and the two teams come to blows.
Felicity and Alena find the proof showing that Oliver didn’t kill Cayden’s son… and Cayden demands that the heroes turn over his three former allies, believing one of them is responsible.
Vince undertakes a risky mission to obtain the location of the thermobaric bomb for Team Arrow. Meanwhile, Dinah remembers how she met Vince and how they gained their powers.
Cayden James ups the ante by launching his plan to take control of every aspect of the city. Despite the scope of Cayden’s plan, Oliver is determined to foil it with just the Original Team Arrow – and without the aid of Rene, Dinah, or Curtis. But things get complicated when William is endangered as a result of Cayden’s handiwork.