S07E02: The Longbow Hunters

In order to track down Diaz from inside prison, Oliver realizes that will require aligning with an old enemy. Meanwhile, in Star City, Felicity's attempts to root out Diaz are thwarted by Diggle, whose allegiance to ARGUS now requires him to keep civilians like her on the outs. Realizing that she can no longer rely on her old team or old methods, a clear-eyed Felicity resolves to find a new way to go after Diaz.