Cyrus Vanch, a nefarious criminal, is recently released from prison and intends to re-secure his position as leader of the underworld. His first step is to take down his biggest opponent in the city - Arrow. Meanwhile, Oliver shows Moira his father's notebook and questions her about the names on the list. Thea is miserable as she starts her internship with Laurel at the legal aid office and Detective Lance makes a deadly mistake that puts Laurel in the crosshairs of Vanch.

Oliver and Diggle learn that Deadshot is still alive and his next target is Malcom. Malcom invites Tommy to attend a benefit honoring Malcom for his work with Starling City but Tommy refuses to attend. Oliver encourages his friend to mend his relationship with his father while he can. Meanwhile, Oliver struggles to balance his new relationship with McKenna and his duties as Arrow.

Oliver and Diggle race to stop the Dark Archer from unleashing his vengeance on The Glades. However, they run into a roadblock after Detective Lance picks up Felicity for questioning. Tommy and Oliver's already tumultuous relationship takes a turn for the worse after Oliver makes a confession about Laurel. After hearing of the danger in The Glades, Thea races to find Roy, inadvertently putting herself directly in the line of fire for Malcolm's devious plan. On the island, Oliver, Slade and Shado are locked in a life-or-death struggle against Fyers as his missiles lock on a full Ferris Air jetliner.

Diggle and Felicity travel to the island of Lian Yu in search of Oliver, who left Starling City after the devastation of The Undertaking and his failure to avert it. Convinced to return home, Oliver finds that things are in much worse shape than he imagined – Isabel Rochev is preparing a hostile takeover of Queen Consolidated, Thea refuses to visit Moira in jail, Roy is trying to fill the void left by the Arrow's absence, and Laurel is working with the District Attorney's office to take down the vigilante. Meanwhile, flashbacks to the island show Oliver's mentors Slade, Shado and Oliver in a desperate situation.

Thieves hijack medical supplies sent to Glades Memorial. Oliver gets into a heated battle with China White and her new partner, the Bronze Tiger, over the supplies. Meanwhile, Laurel makes plans to catch the Arrow; and Thea give Roy an ultimatum.

Sara and Roy become prisoners at the Slade and the only one who is able to save them is Oliver Queen.

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.

After Roy confesses that he's the Arrow, Oliver is forced to lie low as Quentin continues his quest to prove that Oliver is the real Arrow. Meanwhile, a metahuman kills two bank guards and Oliver is forced to turn to Ray--as the Atom--for help.

A heartbroken Cupid returns to Star City with one goal – to destroy anyone in love. The team learns she’s killing couples on their wedding day so Oliver and Felicity decide to pose as bait.

A deadly new criminal, Tobias Church, threatens Star City, which forces Oliver to consider forming a new team of superheroes to help him do battle. In flashbacks, Oliver faces off against the Bratva in Russia.

China White, Cupid and Liza Warner break out of Iron Heights and head to Star City for revenge. Oliver tries to bring in the newly formed girl gang but the ACU intervenes mid-fight. To his surprise, they are there to arrest the Green Arrow for the murder of Det. Malone. Meanwhile, Lance feels responsible for the prison break after Warner tells him she heard about him working with Damien Darhk.

Oliver faces his biggest challenge yet as mayor. Felicity continues down her dark path with Helix. After Vigilante attacks Oliver while he's acting as the mayor, Diggle leads the team in a mission to stop Vigilante once and for all.

Oliver gets closer to the truth about Prometheus. Meanwhile, Helix refuses to continue helping Felicity until she does a favor for them.

Oliver deals with the fallout of the explosion on the island.

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.