Oliver Queen struggles to balance his roles as Green Arrow, mayor, and father after the explosion on Lian Yu. With John Diggle suffering from nerve damage, the team faces new challenges as they question Oliver’s leadership. The arrival of FBI agent Samanda Watson complicates matters as she investigates vigilante activity in Star City.
Cayden James, a vengeful hacker, forms a dangerous alliance with Black Siren, Anatoly, and Ricardo Diaz. They threaten Star City, forcing Oliver to rely on his team despite their fractured trust. Felicity works with Curtis and Dinah to stop Cayden, but tensions rise as secrets and betrayals surface.
Diaz betrays Cayden and takes control of the criminal underworld, proving to be a ruthless adversary. Oliver’s team splinters, with some members questioning his methods. A civil war erupts among the vigilantes, testing loyalties and friendships.
Oliver is arrested by the FBI, revealing his identity as the Green Arrow to secure his team’s freedom. He makes a deal to work with Agent Watson, but Diaz continues to manipulate events from prison. The team reunites to stop Diaz once and for all.
In the final battle, Diaz is defeated, and Oliver regains his team’s trust. However, his deal with the FBI forces him to leave Star City. The season ends with Oliver in custody, while Felicity and William go into hiding, setting the stage for a new chapter in their lives.