After surrendering to the police for being the Green Arrow, Oliver tries to survive in the prison while a new unknown vigilante emerges in the Star City.
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.
Still in prison, Oliver faces his biggest challenge yet. Meanwhile, Felicity gets an intriguing offer, and Diggle asks Curtis to go undercover for ARGUS.
Oliver makes a drastic move in his quest to find Diaz. Like her husband, Felicity pulls out all the stops to get to Diaz. Meanwhile, when arsonists target Rene's community center, injuring Zoe in the process, the mysterious new Green Arrow swoops in to help save the day. Faced with pressure from the mayor to capture the vigilante, Dinah must decide if following the rules at all costs is the best plan to keep the city safe.
Felicity learns something new about Oliver that shocks her. Meanwhile, Diggle asks Curtis to go undercover for ARGUS. Dinah works with an unlikely ally.
Slabside becomes even more dangerous after a guard is cuddled and everyone is a suspect. Felicity enlists help from a surprising source in her pursuit of Diaz, and Laurel flexes her muscles as the District Attorney.
Oliver makes a choice that will affect his entire life, as well as the lives of everyone he cares about.
Felicity stands by her recent decisions regarding her family; Diggle and Lyla continue to look into the Dante painting that Curtis found.
With Oliver and Barry still stuck in the other's bodies, the two get a lead on John Deegan and head to Gotham City with Supergirl to figure out why their reality has changed. While there, they meet the mysterious Kate Kane who provides them with information that leads the group to Arkham Asylum.
Oliver is ready to get back to work with the SCPD and to focus on his marriage with Felicity. However, when Dinah tasks Oliver with tracking the new Green Arrow things take a surprising turn. Meanwhile, Diggle and Lyla must answer to ARGUS about Diaz.
The past comes back to haunt both Oliver and Laurel. Curtis is upset when he discovers that Diggle and Lyla have restarted The Ghost Initiative with Diaz, China White, Kane Wolfman and Carrie Cutter.
As a camera crew follows Oliver and team around to talk about their past as vigilantes and what the Green Arrow means to Star City, Oliver must also deal with William's return from boarding school as well as a new threat to the city. The episode will feature "documentary footage" captured by the BTS crew and interviews from those who have worked alongside the Green Arrow.
Oliver and Felicity are disappointed after they learn that William is hiding something from them. Wanting to focus on his family, Oliver steps back from his Green Arrow duties and let's the team take over tracking down a serial hugger. However, when the team becomes targets for the hugger, things take a bloody turn.
After months of covertly pursuing Dante, Diggle and Lyla finally have a solid lead on the elusive terrorist, so they deploy the ARGUS Ghost Initiative to apprehend him. Meanwhile, Oliver tries to bond with Emiko.
Team Arrow attempts to work with the Star City Police Department but much to Oliver's frustration, things don't go as planned. Meanwhile, Dinah gets some life-changing news.
Mia and William venture into the Glades on a dangerous mission. There they run into Dinah, Roy and Zoe who deliver some devastating news. The flash forwards share highlights from Mia's childhood with Felicity.
Laurel learns about some damaging information that affects Emiko. Always looking to protect his sister, Oliver invites Laurel to help investigate, which makes Felicity happy as her friend is now working with the team. However, when things go awry, Felicity is forced to make a choice between the team and Laurel.
After being accused of hug and having her criminal past exposed, Laurel goes full Black Siren and teams up with an old criminal acquaintance, Shadow Thief, to go on a crime spree around Star City. While Dinah aims to bring Laurel in, Felicity refuses to give up on her friend and tries everything to get through to her, even summoning Sara Lance for help. However, Laurel rebuffs all her efforts, forcing the former friends to face off against each other.
After the Ninth Circle delivers a major setback for Team Arrow, Diggle reluctantly reaches out to a Four-Star General of the Defense Intelligence Agency for help, despite unresolved tension from their past. Meanwhile, Oliver discovers a piece of information that he believes will turn Emiko against the Ninth Circle. Alena returns with an interesting proposal for Felicity.
When they learn of an upcoming attack on the city, Team Arrow calls Roy Harper to help them stop the Ninth Circle. However, things go awry and there is massive collateral damage. As Captain of the SCPD, Dinah investigates what happened in an episode that takes on a true crime narrative and tone.
Oliver finds himself in a precarious position. SCPD shows up with a warrant for Felicity.
The battle between Oliver and Emiko comes to a boiling point which brings back some familiar faces and leaves others in dire jeopardy.