Billionaire playboy, Oliver Queen, has been considered dead for five years. Now, he has returned. But something, during those five years, has changed him into a mysterious green hooded archer.

Arrow moves further along his father's list while battling family issues with his mother, Moira, and especially with his sister. He also makes amends for past difficulties with Laurel.

A mysterious sniper called Deadshot is taking out bidders at an auction for an industry company. The bidders include Oliver's stepfather, Walter Steele.

Peter Declan has been charged with murdering his wife, and only Oliver believes he's innocent. Arrow asks Laurel to look into Declan's case. Meanwhile, Walter investigates a warehouse that Moira mysteriously bought with the company's money.

Oliver is accused of being the hooded archer and is put under house arrest. Also, he thinks back to his time on the island, where he first met Edward Fyers and Deathstroke.

A new vigilante is killing off the people that work for mob boss Frank Bertinelli.

Oliver Queen attempts to train Helena Bertinelli in the hopes that she will join him in his fight for justice. Meanwhile, Walter Steele delves deeper into his wife's secrets.

Oliver Queen attempts to track down a mysterious copycat vigilante who is killing people on the list.

After taking a mob accountant's laptop, Oliver plans to return the money to its rightful owners. Felicity however finds that Dominic Alonzo - the operator of an illegal casino and the head of a gang known for kidnapping - was paid $2 million to kidnap Walter. Arrow pays him a visit and is told that Walter is dead. He tells his mother and Thea but Moira rushes to Malcolm Merlyn demanding to know why he broke their agreement. He assures her that Walter is alive and will be released as long as she continues to cooperate. Oliver is listening to the entire conversation and now knows that his mother is involved, just as Digg had warned him. Flashbacks reveal Malcolm's plan and also the the sinking of Robert Queen's luxury yacht was no accident. Laurel meanwhile tries to make up with Tommy and finally learns the real reason he broke up with her.

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.

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

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.

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.