Oliver must fight to maintain his vow not to take a life when Slade kidnaps someone close to him. Meanwhile, it's Thea who turns to Roy for help, and Diggle takes on ARGUS.moreless
As Slade unleashes his wave of Mirakuru-enhanced soldiers on Starling City, Oliver and his team prepare to take them on. Meanwhile, Malcolm returns to town to meet his biological daughter.
Oliver decides the best way to protect everyone in the crossfire is to surrender himself to Slade before his friends are hurt further. When they realize what Oliver plans to do, Diggle and Felicity band together to stop him. Meanwhile, Laurel renews her investigation into Blood's activities, and Thea considers leaving Starling City.moreless
When Roy kills a man under the effects of Mirakuru, Oliver and Sara disagree on how to stop hm. Meanwhile, Thea tries to lure Roy to Verdant in the hopes that his feelings for her will let him combat the serum.moreless
Oliver attempts to protect his family after Slade launches the next stage of his plan for revenge for Shado's death and Oliver's betrayal. However, one of Oliver's team questions whether Oliver is seeing clearly. Meanwhile, Isabel schemes to take control of Queen Consolidated.moreless
The Huntress returns to town to kill her father, who has been arrested. Oliver promises Sara that he'll stop his ex-girlfriend. However, when Huntress takes a courthouse hostage, including Laurel, Sara steps in. Meanwhile, Roy realizes the cost he must pay to keep Thea safe.moreless
A.R.G.U.S. recruits Diggle to take down a former acquaintance who is now planning to take over Afghanistan. However, he discovers that his new team will consist of three criminals that he formerly put away: Deadshot, Bronze Tiger, and Shrapnel. Meanwhile, Oliver pushes away Sara as he prepares for his battle with Slade.moreless
Stephen is still walking a fine line with his ULTRA partner Hillary who continues to question his loyalties.
When ULTRA and The Tomorrow People both learn of a breakout using her powers to benefit humans both sides seek her out to join their cause.
Meanwhile Morgan takes a risk and betrays Jedikiah's trust to help The Tomorrow People but Jedikiah learns something from her that is an even bigger surprise.
Oliver discovers that Slade is alive and intends to get revenge for Oliver's actions against him on the island. Meanwhile, in flashback Oliver and Sara prepares to take the Amazo, but Sara tells Oliver that he must kill Ivo to keep the doctor from revealing to Slade who is responsible for Shado's death.moreless
Julian returns with a vengeance but when he's caught by ULTRA he is forced to strike a deal that could cost him and Stephen their lives.
John disobeys Cara's orders again when he learns Julian has discovered the location of The Tomorrow People's lair.
Meanwhile still plagued by nightmares from her near death experience Astrid turns to John for comfort and support.
A villain nicknamed the Clock King stalks Starling City, committing precision crimes. Meanwhile, Laurel hosts a dinner party for her family but things go badly, and on the island Sara befriends a dying pilot.moreless
After receiving some shocking news Stephen attempts to restore order in both his worlds by striking a deal with Jedikiah.
Cara and Russell contend with a new break-out and must also deal with an ULTRA trap.
Meanwhile Jedikiah is closer to developing a secret technology that could change his future.
Oliver and Quentin try to convince Sara to stay in Starling City to help Laurel as she tries to deal with her drug addiction. However, Sara soon realizes that she is putting her family in danger when a member of the League of Assassins abducts Dinah and threatens to kill her if Sara doesn't return to the fold.moreless
Stephen is upset with Jedikiah for going back on his word, forcing him to face The Founder.
In order to protect Astrid, Stephen must make a deal to bring in a powerful break-out and elsewhere John clashes with Cara which forces her to issue a harsh punishment.
Bronze Tiger escapes from prison and goes after a prototype of Malcolm's earthquake machine. Meanwhile, Roy refuses to train with Arrow unless the vigilante reveals his true identity, Laurel is disbarred, and Thea tries to get Walter and Moira to reconcile.moreless
Stephen feels uneasy about fellow ULTRA trainee, Hillary, who has her own secret agenda. After his mother insists the family go camping with Peter, Stephen asks John and Cara to ensure everything is okay with Astrid while he's gone.
Laurel reaches out to Arrow for assistance in investigating Sebastian Blood, but he has her arrested for her drug use when she gets too close to his secrets. Meanwhile, Roy almost kills a man when he loses control of his newfound strength. In the past, Sarah tells Oliver a secret about her older sister.moreless
Stephen and his fellow ULTRA trainees are given a test by Jedikiah to determine their worthiness as Agents but not everyone is happy to work as a team.
Cara is faced with a visitor from her past and John works with a new breakout while Russell is sent on a dangerous recon mission that could force a clash between different groups of Tomorrow People
A new villain, Shrapnel, arrives in Starling City and his next target is Sebastian Blood. With Arrow trapped, Diggle must try and help the alderman. Meanwhile, Thea learns about Roy's new abilities and Laurel investigates the connection between Blood and Cyrus Gold, the man who murdered her father's friend.moreless
After a battle with Cyrus Gold, Oliver is poisoned and left for dead, and Felicity gives him an antidote that causes hallucinations of his past. Meanwhile, Brother Blood captures Roy, Barry continues assisting Felicity, and Lance loses someone when he tries to run surveillance on Cyrus.moreless
When John finds himself in a dangerous situation Stephen finds he is unable to help without revealing his duplicity to ULTRA. Also not satisfied with the answer he discovered about his father's death Stephen decides to take drastic action to find the truth with help from his fellow Tomorrow People.
Cara and Russell negotiate a trade with Jedikiah which ultimately makes Jedikiah take a big risk.
Stephen is determined to uncover what he hopes is the key to finding his father, and crafts a plan with The Tomorrow People that involves getting inside Jedikiah’s head. Meanwhile, Cara and Russell encounter an uninvited visitor in the subway tunnel base.
Stephen takes a risky opportunity and snoops around ULTRA.
Police scientist Barry Allen travels to Starling City to investigate a seemingly impossible robbery from Queen Consolidated's Applied Science Division, and Felicity takes a liking to him... much to Oliver's dismay. Meanwhile, Sin asks Roy for help tracking down a missing friend, and Thea joins her boyfriend in the hunt, only for one of them to be injured.moreless
A deadly illness sweeps through Starling City. When Diggle is struck down, Oliver confirms that the source of the illness is a new version of Vertigo. Tracking down a lead, Felicity is soon captured by The Count, who has escaped prison. Meanwhile, Moira fights for her life in the courtroom against a death sentence, and Laurel is forced to prosecute her when DA Donner is stricken down by the same illness.moreless
After Stephen decides to have some fun with his newfound powers, Jedikiah takes extreme measures to ensure it doesn't happen again.
John feels tension between himself and Cara after he and Russell return from their trip while Stephen decides to try and handle a dangerous new breakout on his own but finds himself in over his head and needing help from his fellow Tomorrow People.
Stephen becomes even more determined to find out what happened to his father after having a moment of clarity about him.
A.R.G.U.S. recruits Diggle to rescue Lyla, who has disappeared in Moscow following a lead on Deadshot. Oliver and Felicity volunteer to go with their friend, but run into trouble when Isabel insists on accompanying them. Meanwhile, Moira's attorney suggests that Thea stop dating Roy because it's hurting Moira's defense.moreless
Stephen and Russell head out for a night of fun only to run into a potential new breakout. They report back to John and Cara about the discovery but want to keep a low profile from ULTRA.
Russell learns of his father's death and struggles with the decision of whether or not to return home. John volunteers to go with him to keep him out of trouble.
Meanwhile Jedikiah has a secret that could destroy his career.