A jewel thief named Dodger strikes Starling City, a purse snatcher targets Thea and dating anxiety hits Oliver and Diggle. Each perilous situation leads to hard choices.

Helena is back to seek vengeance, but Oliver still has feeling toward her. The Arrow must stop and kill her, but at what costs? Now that several of his closest friends know about his true identity, no one is safe.

After a major fire, Oliver decides it's time to eliminate real estate developer and slumlord John Nicol, another person on his father's list. He's beaten to the punch when another vigilante, The Savior, who kidnaps Nicol and ultimately executes him - broadcasting the whole thing over the Internet. The new vigilante is identified as a man whose wife was killed in a bodega robbery in the Glades district. When he kidnaps Thea's new boyfriend, Roy Harper, Oliver decides to stop him. Meanwhile, Laurel is upset to find that her father has come around to her mother's belief that her sister may still be alive. In a flashback to his days on the island, Oliver learns why Yao Fei refused to leave.

Oliver decides that his next target is going to be someone on Digg's list: Deadshot. They set a trap for him and Digg's spy friends get involved as well. Meanwhile, Laurel's latest clients are Eric and Nancy Moore who have agreed to testify against Edward Rasmus, a financial advisor who swindled them. The night before their deposition however, they are assassinated. Laurel takes charge of their now orphaned son, Taylor, but he saw his parents killed and is now the assassins next target. Oliver steps in to stop him but in doing so fails to back up Digg and Deadshot escapes. It creates a rift and Diggs walks out. A flashback to the island show Oliver, Wilson and Shado are preparing to free Yao Fei.

The time is fast approaching for the Undertaking to occur and Malcolm Merlyn begins to tidy up the loose ends, beginning with the scientists at UNIDAC. Oliver and Digg trick Moira into telling just what the Undertaking is about. Oliver realizes that even if he manages to eliminate everyone on his father's list he has only, in his own words, eliminated the symptoms and not the disease. Felicity locates the UNIDAC device - sort of. Thea and Roy's relationship comes to head when they are unable to locate the vigilante. Walter files for divorce. Laurel and Oliver begin a new relationship. In a flashback to his time on the island, Oliver learns just what Edward Fyers' plan is.

Oliver awakens to find himself Malcolm Merlyn's prisoner. He manages to escape and away with help from Digg. Malcolm accelerates his timetable as a result. Felicity is questioned by Det. Lance about her hacking activities but is interrupted by Oliver who tells him about Malcolm's plan to destroy the Glades. Tommy confronts Oliver about Laurel but refuses to believe that his father is up to no good. Malcolm comes clean about his plans and Tommy realizes that his father is insane. Moira goes public with what she knows, urging the residents of the Glades to evacuate. Roy and Thea get caught up in the mayhem. While Oliver and Digg go after Malcolm, Felicity tries to neutralize the device via Lance. Malcolm has planned it all very well, however. In a flashback to his time on the island, Fyers attempts to bring down an airliner.

Diggle and Felicity return to the island to convince Oliver to return as the Arrow.

Now that Oliver no longer has the list to work from, he's not sure what's next. Roy continues doing his own vigilantism and has to be bailed out of jail by Thea. When he mentions to Oliver that someone is hijacking medical deliveries to the Glades Memorial hospital, the Arrow knows exactly what he wants to do. His visit to the hospital doesn't go well when local politician Sebastian Blood takes him to task for what his family has done. When he tries to stop a hijacking, Arrow comes up against China White and her new partner Bronze Tiger. Thea tells Roy she's not going to wait around until he gets killed. The flashback to the island shows the aftermath of Oliver's violent attack on the unknown visitor. Shado takes him in hand.

When a dangerous criminal from Lance's past (MICHAEL EKLUND) escapes from prison, Felicity offers herself up as bait so Arrow, Diggle and Lance can capture him...but plans go awry.

Oliver discovers a man who goes by the name "The Mayor" is bringing illegal guns in to The Glades, so Oliver sponsors a "Cash for Guns" event to help clean up the city. Unfortunately, The Mayor crashes the event with his gang and seriously injures Sin. The Canary is furious when she learns her friend is in the hospital and sets out for revenge. Meanwhile, Felicity stuns Oliver with a bit of information about the Canary, Donner asks Laurel to dinner, and Diggle reconnects with an old friend.

While Oliver tends to the Canary's wounds, he tries to get her to talk about where she came from but she refuses. However, after Oliver and Canary are attacked at the Queen mansion by a trained killer from the League of Assassins, she confesses to how she's connected with the nefarious group. Meanwhile with Moira facing multiple counts of murder and conspiracy for her part in the destruction of The Glades, the Assistant District Attorney offers her a choice - plead guilty now and avoid the death penalty or take your chances in court. Thea begs her mother to fight for her life but Moira seems resolute about taking the offer. Meanwhile, Oliver is furious with Laurel for joining the prosecution's team on his mother's case.

Amanda Waller sends A.R.G.U.S. agents to kidnap Diggle. Waller informs Diggle that Lyla has gone missing after following a lead on Deadshot in Moscow. When Diggle tells the team he's headed to Russia to rescue Lyla, Oliver and Felicity decide to join, but things get messy when Isabel shows up on the tarmac and insists on joining Oliver's "work trip". Meanwhile, Moira's lawyer, Jean, tells Thea that dating Roy, a known criminal, is hurting her mother's case.

Oliver is concerned when a mysterious illness sweeps the city, infecting hundreds of people, including Diggle. Oliver discovers Vertigo in Diggle's blood and realizes The Count has broken out of prison and is once again distributing his drug. Meanwhile, Moira goes on trial for her participation in the Undertaking. ADA Adam Donner collapses in court with Vertigo symptoms so Laurel must step in and try the case against Moira. Oliver is torn between standing by his family during the trial and catching The Count. However, things change when Felicity follows a lead and walks straight into a trap set by The Count.

After an impossible break in at Queen Consolidated, CSI Barry Allen comes to Starling to help with the investigation, Sin asks Roy for help so Thea tags along.

After a fight with Cyrus Gold, aka the Acolyte, Oliver is drugged and left for dead. Determined to cure him, Felicity makes a risky decision. The cure causes Oliver to hallucinate, and what he sees forces him to confront his past. Meanwhile, Barry Allen continues to help Felicity, and their connection grows stronger. The Arrow asks Quentin to look into Gold, but when the stakeout on Gold goes bad, someone is killed. Roy is captured and tortured by Brother Blood.

Oliver must tackle a new threat to the city when bombs start to go off in Starling City. Felicity discovers the person setting them off is Mark Scheffer, a man who goes by the nickname Shrapnel. The Arrow discovers Shrapnel's next target is Sebastian Blood's "Unity Rally" and tries to talk the alderman out of hosting it, but he refuses. The Arrow sets off to stop the bombing, but Shrapnel tricks him and traps him in a bomb-laced antique store where he is unable to move without setting off the device. While Felicity helps Oliver, Diggle races to the plaza to find the bomb before it goes off. Meanwhile, Roy continues to hide his new strength from Thea but, after she witnesses his super strength in action at the rally, she demands answers. Laurel's suspicions about Sebastian grow stronger once she learns that he grew up with Cyrus Gold, the man who killed Lance's partner. After Donner refuses to help her investigate, she turns to The Arrow for help.

When Laurel asks the Arrow to investigate Sebastian Blood, Oliver is unsure whether to believe her accusations. But when they get too close to the truth, Blood strikes back.

Arrow offers to train Roy so he can learn to control his newfound super-strength. However, Roy is a rebellious student and refuses to listen unless Arrow reveals his true identity, which Oliver refuses to do. Meanwhile, the Bronze Tiger escapes from prison and steals Malcolm's earthquake machine to sell to the highest bidder. Oliver, Diggle and Felicity attempt to stop the transfer, but Roy gets in the way, putting everyone in danger. Laurel is disbarred and spirals out of control. Moira is thrilled when Walter asks her to dinner, but his reason surprises her. Thea encourages her mother to ask Walter to reconcile.

Laurel continues to unravel, Oliver and Lance try to convince Sara to stay in Starling City and finally reunite with Laurel and Dinah. However, Sara's fellow League of Assassins member, Nyssa, comes to bring Sara back to the fold, but when Sara refuses, Nyssa kidnaps Dinah. Realizing she's putting her family in danger by staying in town, Sara considers re-joining the league.

Oliver brings Sara into the Arrow team. Watching Oliver and Diggle spar with Sara and talk old scars, Felicity starts to feel left out. The team is investigating a villain named William Tockman, a.k.a. The Clock King, who is a brilliant thief armed with technology that can open any bank vault in Starling City. After The Clock King infiltrates the computer systems in the lair, Felicity feels pressure to prove her worth. When she gets a lead on Tockman's whereabouts, she heads out without the team, putting her in peril. Meanwhile, Oliver throws Sara a welcome home party, but Laurel refuses to attend. After Lance makes his case for a family dinner, Laurel acquiesces, but when Oliver shows up with Sara, she loses her temper on both of them.

Oliver is shocked when he learns that Slade has come to Starling City. Back on the island, as Oliver, Slade and Sara prepare to take over the freighter from Ivo, Sara pulls Oliver aside and tells him he needs to kill Ivo to prevent him from telling Slade what happened with Shado. Oliver feels immense guilt over the situation but realizes Slade's growing rage from the Mirakuru makes him unpredictable and he could turn on his friends if he thinks Oliver is to blame. Oliver agrees to kill Ivo and the battle begins.

Lyla asks Diggle to go on a mission alongside the Suicide Squad, a team assembled by Amanda Waller to undertake high-risk missions, even though the team includes Diggle's nemesis, Deadshot, and Oliver's enemy, Bronze Tiger.

When Frank Bertinelli is arrested, Oliver knows it's only a matter of time before his daughter, Helena, AKA The Huntress, returns to town. To make matters worse, Laurel is picked to try Frank's case, putting her right in the path of Helena. Oliver tells Sara he will handle his ex-girlfriend, but when Helena takes hostages at the courthouse, including Laurel, the Canary will stop at nothing to save her sister. When The Huntress and Canary meet, an epic battle begins. Meanwhile, Roy realizes he needs to keep Thea safe, but doesn't like the way he is forced to go about it.

After taking a ride home from Slade, Thea becomes his prisoner. Can Oliver and his friends save her? Also, someone close to Oliver is working for Slade, since his return from the Island after Tommy's death.

Oliver, Canary, Diggle, and Felicity return to the lair and find Slade waiting for them. An epic battle breaks out and one member of Team Arrow is sent to the hospital. Thea hits her breaking point, but just as Oliver is about to reach her, Slade intervenes and Oliver is faced with a choice - his battle with Slade or his family. Meanwhile, Laurel struggles with a new secret.

The mirakuru sends Roy into a rage rampage across the city. Sara thinks that the only way to stop him is to kill him but Oliver thinks he can still save him. Meanwhile, Slade is continuing his plan to make Oliver pay.

After Slade threatens to take everything Oliver loves away, Oliver decides the fastest way to stop further bloodshed is to surrender to his enemy. Knowing that surrender will surely lead to Oliver's death, Diggle and Felicity go to extreme measures to keep Oliver from confronting Slade. Meanwhile, Thea considers leaving town, and Laurel resumes her crusade against Sebastian Blood. Finally, Slade unleashes his assault on Starling City.

Oliver rallies his team as Slade's soldiers attack the city. Felicity gets a call from S.T.A.R. Labs with game-changing news and Thea comes face-to-face with her father.

As Oliver's face off with Slade escalates, his resolve to the no-kill rule is tested. Especially as Slade targets the woman Oliver loves.

As a new enemy emerges seven months after Slade's attack upon Starling City, Oliver battles with the help of his teammate Roy. However, with the Arrow's presence elsewhere someone he had loved dearly is hurt.

Team Arrow is in pursuit of a new villain who poses a threat to Starling City. Meanwhile, Oliver is worried about not having heard from Thea.

Oliver, Roy and Diggle fly to Corto Maltese to find and convince Thea to come back home to Starling City, Lyla sees this as an opportunity and asks Diggle to locate an A.R.G.U.S. field operatives there.

Nyssa and Oliver join forces to go after the Dark Archer.

Felicity's family and backstory come to the fore. Felicity tries to find common ground with her mother but it is clear the two are very different.

Ted Grant becomes the primary suspect when a body is found in the Wildcat gym and Roy shares a secret with Felicity.

Oliver must stop an Arrow-obsessed serial killer, Carrie Cutter, who is convinced that The Arrow is her one true love and will stop at nothing to get his attention. Unfortunately, her way of getting his attention is to kill people. Meanwhile, Ray asks Felicity to be his date for a work dinner with important clients. Thea auditions new DJs for Verdant and meets Chase, a brash DJ with whom she immediately clashes.

As Oliver, Arsenal, and Diggle pursue a killer named Digger Harkness, they encounter an ARGUS team; Oliver and the Flash team up to try and stop Harkness.

The League of Assassins give Oliver 48 hours to find Sara's killer, or Starling City citizens will die. Oliver then has an epic confrontation with Ra's al Ghul.

The Team's worst fears are realized when Merlyn informs them of Oliver's death. Meanwhile Ray Palmer tests part of his ATOM suit out and Laurel Lance decides to pursue justice outside of the law by taking up the mantle of the Black Canary.

Arsenal and Diggle confront Laurel about trying to step into her sister's shoes and warn her to stop before she gets herself killed. However, the villan Brick kidnaps the city's Aldermen and threatens to kill them all unless the police evacuate The Glades, it's all suits on deck. Meanwhile, Ray steps in to help Lance and the police force fight Brick, showing Felicity a new side of her boss. Malcom tells them that Ra's al Ghul is after his family and they must leave town immediately.

Still operating without Oliver and desperate to stop Brick, Team Arrow is forced to consider Malcolm's offer to help shut Brick down as Malcolm has a personal score to settle with the felon. Roy and Laurel point out that the team could use some help to save the innocents of The Glades, but Felicity is adamantly against it. They look to Diggle to make the final decision. Meanwhile, the flashbacks chronicle Malcolm's descent from kind-hearted father and husband to cold-blooded killer after the murder of his wife.

Oliver struggles to adjust to the changes that have taken place within Team Arrow; Laurel ignores Oliver and pursues Vertigo - who injects her with the drug; Thea receives a surprise visitor.

Malcolm puts Oliver and Thea in a dangerous situation that lands them on Lian Yu with Oliver's former enemy, Deathstroke. A flashback reveals when Oliver and Maseo returned to Starling City to retrieve the Omega bio weapon, and despite being under strict orders from Amanda Waller not to reveal himself to anyone, Oliver looks in on his family, Laurel and Tommy.

Malcolm is captured by Ra's al Ghul and taken to Nanda Parbat. Because of his love for Thea, Oliver considers saving Merlyn. Ray is obsessed with finishing his Atom suit so he can save the city but Felicity fears he is heading down the same path as Oliver and tries to pull him out of the lab.

Oliver thinks about the offer Ra's Al Ghul gave him, but to do so theres a catch.

It's celebration time as Diggle and Lyla get married. However, Deadshot interrupts their honeymoon and tells them the Suicide Squad has been given a new mission - rescue United States Senator Joseph Cray from a hostage situation in the Republic of Kasnia. Amanda Waller breaks down the mission and introduces them to the newest member of the Suicide Squad, Cupid. Meanwhile, Oliver learns about Ray's new Atom costume and the two have a heated stand-off. Felicity and Ray hit a rough patch.

During an attack on the mayor's office, Ray is critically injured. Felicity is pleasantly surprised when her mother, Donna Smoak, shows up at the hospital to offer her support. With the SCPD out in full force looking for the assailant, Oliver and his team work hard to stay one step ahead of the police to find the man responsible. However, things come to a head when Ra's al Ghul kidnaps Captain Lance.

Lance continues his mission to take down the Arrow. When a meta-human named Jake Simmons, who kills people with blasts of energy and plasma, starts terrorizing Starling City, Oliver is forced to ask Ray for help.

Ra's al Ghul finally makes Oliver an offer he can't refuse. The team joins Oliver on his journey to Nanda Parbat where a heartbroken Felicity decides to take matters into her own hands.

Oliver goes through a transformation; Laurel asks Felicity and Diggle to help Nyssa face the League of Assassins.

Oliver must complete two final tasks before becoming the next Ra's al Ghul; Nyssa is threatened; Malcolm makes an offer to the team; Thea visits Roy.

Ra's al Ghul sets his plan in motion, putting everyone in danger; Oliver must decide if he is strong enough to handle his new role - and what it will mean for his team and his soul.

The team faces off against a formidable villain nicknamed The Calculator (guest star Tom Amandes). Meanwhile, Nyssa (guest star Katrina Law) makes her move and Roy Harper (guest star Colton Haynes) returns to Star City.

Roy Harper returns to Star City and Oliver and Thea take action to save him when they discover the reason why he's come back.

Nyssa al Ghul returns to Star City to let Thea know that a group of renegade League of Assassins members are planning to attack her.

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.

Felicity is determined to find Diaz by any means necessary when Diggle tries to keep her on the outs and Oliver is forced to ally with an old enemy.

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 and Felicity each make drastic moves to find Diaz; the new Green Arrow swoops in when arsonists target Rene's community center; Dinah faces pressure from the mayor to capture the vigilante.

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 murdered 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. Meanwhile, Diggle and Lyla continue to look into the Dante painting that Curtis found.

Still trapped in each other's bodies, Oliver and Barry head to Gotham City with Supergirl to find out why their reality changed and cross paths with the mysterious Kate Kane.

Oliver wants to get back to work and focus on his marriage but gets sidetracked by offering to track down the new Arrow; 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.

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 killer. However, when the team becomes targets for the killer, 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 go on a dangerous mission; Dinah, Roy and Zoe deliver some devastating news; 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 murder 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; things do go awry and there is massive collateral damage; Dinah investigates what happened.

Oliver finds himself in a precarious position; S.C.P.D. 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.

Upon learning the key to oppose The Monitor, Oliver and team return to Russia on a mission to gather the necessary materials. Connor reunites with a figure from his past.

Oliver's mission takes him to Lian Yu where he tries to ignore the repercussions of the looming Crisis until he receives help from an old friend. Meanwhile, a united Team Arrow faces a recognizable villain.

The final events in the story of the Green Arrow.

Lance continues his mission to take down the Arrow. When a meta-human named Jake Simmons, who kills people with blasts of energy and plasma, starts terrorizing Starling City, Oliver is forced to ask Ray for help.

During an attack on the mayor's office, Ray is critically injured. Felicity is pleasantly surprised when her mother, Donna Smoak, shows up at the hospital to offer her support. With the SCPD out in full force looking for the assailant, Oliver and his team work hard to stay one step ahead of the police to find the man responsible. However, things come to a head when Ra's al Ghul kidnaps Captain Lance.

Ted Grant becomes the primary suspect when a body is found in the Wildcat gym and Roy shares a secret with Felicity.

The team faces off against a formidable villain nicknamed The Calculator (guest star Tom Amandes). Meanwhile, Nyssa (guest star Katrina Law) makes her move and Roy Harper (guest star Colton Haynes) returns to Star City.

Arrow offers to train Roy so he can learn to control his newfound super-strength. However, Roy is a rebellious student and refuses to listen unless Arrow reveals his true identity, which Oliver refuses to do. Meanwhile, the Bronze Tiger escapes from prison and steals Malcolm's earthquake machine to sell to the highest bidder. Oliver, Diggle and Felicity attempt to stop the transfer, but Roy gets in the way, putting everyone in danger. Laurel is disbarred and spirals out of control. Moira is thrilled when Walter asks her to dinner, but his reason surprises her. Thea encourages her mother to ask Walter to reconcile.

When they learn of an upcoming attack on the city, Team Arrow calls Roy Harper to help them stop the Ninth Circle; things do go awry and there is massive collateral damage; Dinah investigates what happened.

After a major fire, Oliver decides it's time to eliminate real estate developer and slumlord John Nicol, another person on his father's list. He's beaten to the punch when another vigilante, The Savior, who kidnaps Nicol and ultimately executes him - broadcasting the whole thing over the Internet. The new vigilante is identified as a man whose wife was killed in a bodega robbery in the Glades district. When he kidnaps Thea's new boyfriend, Roy Harper, Oliver decides to stop him. Meanwhile, Laurel is upset to find that her father has come around to her mother's belief that her sister may still be alive. In a flashback to his days on the island, Oliver learns why Yao Fei refused to leave.

Roy Harper returns to Star City and Oliver and Thea take action to save him when they discover the reason why he's come back.

Helena is back to seek vengeance, but Oliver still has feeling toward her. The Arrow must stop and kill her, but at what costs? Now that several of his closest friends know about his true identity, no one is safe.

A jewel thief named Dodger strikes Starling City, a purse snatcher targets Thea and dating anxiety hits Oliver and Diggle. Each perilous situation leads to hard choices.