With crime at an all-time low, Oliver lets his guard down and is taken by surprise by a new villain; Oliver and Roy take on the Count; Diggle becomes a father; Lance gets a promotion; Laurel joins the inner circle.
Another archer comes to town and targets businessmen; Roy is forced to tell Oliver why Thea left town; Laurel considers sharing a secret with Lance.
When Felicity determines that Thea is in Corto Maltese, Oliver intends to bring her back home; Diggle is double-crossed; Laurel and Ted Grant meet.
Oliver learns that Malcolm Merlyn is alive -- and thinks he was responsible for Sara's death; Laurel avoids Nyssa, believing that Sara's association with the League of Assassins led to her demise.
A cyberattack pushes Felicity and Oliver to their limits -- and brings Starling City to its knees; Felicity's mother visits; Laurel's motives are questioned.
Ted Grant becomes the primary suspect when a body is found in the Wildcat gym; Roy divulges a secret to Felicity.
A woman becomes obsessed with Arrow and begins killing people to get his attention; Ray asks Felicity to accompany him to dinner with important clients; Thea auditions new DJs.
As Oliver, Arsenal and Diggle pursue a killer named Digger Harkness, they encounter an ARGUS team; Oliver and the Flash team up to try to stop Harkness.
Laurel is surprised when her father shows up with a with a special Christmas gift -- her mother, Dinah; Ray tries to make things right with Felicity; Oliver meets with Ra's al Ghul.
As Diggle, Felicity and Roy start to fear the worst after Oliver's disappearance, Merlyn pays them a surprise visit; Ray experiments with part of his new suit; Laurel takes on the role of the Black Canary.
Diggle and Arsenal confront Laurel about her dangerous work as the Black Canary; Felicity sees a new side of Ray as he helps Lance fight a villain who has kidnapped the city's Aldermen.
Still without Oliver, the team is forced to consider Malcolm's offer; more details of Malcolm's life are revealed.
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 places Oliver and Thea in a dangerous situation; a flashback reveals a time when Oliver and Maseo returned to Starling City.
Ra's al Ghul captures Malcolm and takes him to Nanda Parbat; Ray obsesses over finishing his Atom suit, but Felicity tries to get him out of the lab to prevent him from going down the wrong path.
Oliver learns a new villain and his crew have been terrorizing Starling City; Nyssa and Laurel bond over their issues; Lance shuts out the Arrow and Laurel.
Diggle and Lyla's honeymoon is interrupted by the Suicide Squad and a new mission; Oliver and Ray have a heated confrontation about the Atom costume, leading to a rough patch between Ray and Felicity.
Ray is seriously injured when the mayor's office is attacked; Felicity's mother visits to offer support; Oliver and the team's pursuit of the person responsible becomes complicated when Capt. Lance is kidnapped by Ra's al Ghul.
With Lance still targeting the Arrow, Felicity insists that Oliver keep a low profile; a metahuman who uses blasts of energy and plasma to kill people terrorizes the city, forcing Ray and Oliver to team up.
Ra's al Ghul presents Oliver with an irresistible offer; Felicity takes matters into her own hands as the team accompanies Oliver on a journey.
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 coming the next Ra's al Ghul; Nyssa is threatened; Malcolm makes an offer to the team; Thea visits Roy.