Laurel tries to prosecute Martin Somers, a drug smuggler who is on Oliver's list. and responsible for the death of her client's father. Meanwhile, Oliver tries to reconnect with his family while repelling their efforts to put him in charge of Queen Consolidated.
Songs: Jessie Ware -- Devotion, Foy Vance -- Melrose EP, Maroon 5 -- One More Night, Joshua Radin -- Underwater
A new vigilante in Starling City is going after mobster Frank Bertinelli. However, when the vigilante almost hits Moira, Oliver vows to put an end to the newcomer's reign of terror. Meanwhile, Tommy gets a rude surprise from his father.
Songs: Civil Twilight -- Next to Me
Oliver takes Helena under his wing and trains her in how to be a vigilante that seeks justice rather than vengeance. Meanwhile, Tommy continues to have problems after his father cuts him off of his trust fund, and Walter realizes that there is still more to learn about Moira and her secret operations.
When Joanna's brother is killed in a mysterious fire, she asks Laurel for help. Laurel calls the Hood, unaware that Oliver is having a crisis of confidence after the Dark Archer defeated him. While Oliver decides whether to get involved, Laurel and Tommy have issues when Tommy suggests that he move in. Meanwhile, Thea tries to get Moira out of her depression due to Walter's disappearance.
An armored bank robbery puts Oliver on the trial of Ted Gaynor, a man on his father's list... and Diggle's former commanding officer. Meanwhile, Thea suspects that Malcolm and Moira are having an affair, and Malcolm tries to make amends with Tommy.
Starling City is overwhelmed by a flood of a new drug, Vertigo, and Thea is arrested after using it. Oliver sets out to seek down the drug's creator, The Count, only to be dosed with it himself.
Mobster Cyrus Vanch gets out of prison on a technicality and plans to take over the power vacuum in Starling City by taking down the biggest threat: The Hood. Meanwhile, Diggle confirms that Moira is involved with Robert's death, but Oliver refuses to accept his mother's activities. And on the island, Oliver meets a potential ally... if the man doesn't kill him first.
A jewel thief known as Dodger targets rare gems in Starling City. Felicity convinces Oliver to go after the thief, and Oliver bugs McKenna's phone to get the information he needs to find the thief. Meanwhile, Thea runs up against a purse-snatcher and Moira asks a friend for help dealing with Malcolm.
When Moira hires the Triad to kill Malcolm, the Triad hires Deadshot to assist them. Oliver and Diggle soon get word of the assassination attempt and end up trying to save Malcolm, unaware of his connection to the Undertaking. Meanwhile, Laurel receives an unexpected visitor.
Helena returns to town to track down her father and kill him, and needs Oliver to help her. Meanwhile, Oliver tries to balance his personal and his vigilante lives, Thea grows closer to Roy, and Quentin has to decide whether to follow his wife's suspicions concerning their younger daughter.
A new vigilante, The Savior, is capturing and executing those who he believes are preying on the people of The Glades... and Roy is his next target. Meanwhile, Moira must take drastic steps when Malcolm learns who hired his would-be assassin, and Laurel tries to discover the truth about her sister's possible survival.
Miss Jane -- I'ts a Fine Day (Remix), Rihanna
Diggle refuses to work with Oliver, forcing the vigilante to turn to Felicity when he needs to infiltrate a casino whose owner has information on Walter's whereabouts. Meanwhile, Tommy tells Laurel that Oliver still loves her, and in flashbacks Malcolm and Robert disagree on how to bring about The Undertaking.
Songs: Adam Agin -- Your Heart Keeps Burning
As the Dark Archer, Malcolm eliminates the scientists who created the Markov Device and then ships it to Starling City to destroy The Glades. Meanwhile, Oliver, Diggle, and Felicity infiltrate Merlyn Global to learn of Malcolm's plans, and Laurel tries to resolve matters with Tommy. Five years earlier, Fyers tells his captives what his plan is for the missile launcher.