23 Episodes 2015 - 2016 In Season 4 of "Arrow," Oliver Stephen Amell takes up the mantle of "Green Arrow" and begins to work with the city police to take down the Ghosts, a gang led by the powerful Damien Darhk Neal McDonough. In his public life, Oliver is convinced to run for mayor after the other candidates are assassinated or scared away, putting him and his loved ones in the firing line. He also makes a shocking discovery that jeopardizes his relationship with Felicity Emily Bett Rickards. Elsewhere, Laurel Katie Cassidy and Thea Willa Holland convince Malcolm John Barrowman to help resurrect Sarah Caity Lotz; and Felicity does everything in her power to find Ray Brandon Routh. Meanwhile, Quentin Paul Blackthorne and Felicity's mother, Donna Charlotte Ross, get closer; and John David Ramsey finds out the truth about his brother. Episode 8 concludes the crossover from "The Flash," launching sister show "Legends of Tomorrow." Also starring Matt Ryan as John Constantine. Episode 1 Green Arrow Wed, Oct 7, 2015 60 mins Season 4 begins with assassins, led by the evil Damien Darhk, attacking Star City. Oliver quickly returns from a blissful getaway with Felicity to defend the city, but Diggle makes it clear that he doesn't want Oliver on the team. Where to Watch Episode 2 The Candidate Wed, Oct 14, 2015 60 mins The Green Arrow and Speedy try to protect an old Queen family friend, Jessica Danforth, when she decides to run for mayor. Meanwhile, Thea begins to exhibit effects from the Lazarus Pit; and Felicity faces a tough business decision and looks to one of her employees, Curtis Holt, for help. Where to Watch Episode 3 Restoration Wed, Oct 21, 2015 60 mins The growing tension between Oliver and Diggle puts both their lives at risk when they go after Damien Darhk and a deployed meta-human. Meanwhile, Laurel talks Thea into returning to Nanda Parbat to ask her father to put Sara into the Lazarus Pit. However, Laurel is surprised when Nyssa refuses to do it. Where to Watch Episode 4 Beyond Redemption Wed, Oct 28, 2015 60 mins Laurel deals with the repercussions of taking Sara to Nanda Parbat. Meanwhile, Oliver asks Capt. Lance for a favor and is surprised at what he finds out. Where to Watch Episode 5 Haunted Wed, Nov 4, 2015 60 mins Things take a turn for the worse with Sara, so Oliver calls in a favor from an old friend, John Constantine, who deals in the mystical. Where to Watch Episode 6 Lost Souls Wed, Nov 11, 2015 60 mins Felicity becomes frantic when she learns Ray is alive and being held by Damien Darhk. Felicity's guilt over not finding Ray sooner causes tension between her and Oliver. Meanwhile, Sara joins Laurel, Thea and the team on a rescue mission to free Ray. However, the effects of the Lazarus Pit take over and threaten to jeopardize the entire operation. Where to Watch Episode 7 Brotherhood Wed, Nov 18, 2015 60 mins Green Arrow's ongoing battle with Damien Darhk gets complicated by a shocking revelation; Thea's bloodlust returns and she loses control in front of Alex. Where to Watch Episode 8 Legends of Yesterday Wed, Dec 2, 2015 62 mins A crossover episode that began on "The Flash" concludes with Oliver and Barry taking Kendra and Carter to a remote location to keep them hidden from Vandal Savage, while they figure out how to defeat him. Meanwhile, Malcolm arranges a meeting between Vandal, Green Arrow and the Flash, but it doesn't go as planned. Where to Watch Episode 9 Dark Waters Wed, Dec 9, 2015 60 mins Oliver makes a bold move against HIVE when the city is attacked. Meanwhile, Malcolm checks in on Thea and leaves her with a warning; and things take a horrible turn when Damien Darhk retaliates in a brutal manner at Oliver's mayoral holiday party. Where to Watch Episode 10 Blood Debts Wed, Jan 20, 2016 60 mins Oliver seeks revenge and goes on a brutal manhunt to find Dahrk, after dealing with the devastating consequences of Dahrk's latest attack. Where to Watch Episode 11 Wed, Jan 27, 2016 60 mins Diggle must learn to trust his brother Andy when an enemy of their wartime past, an agent of the criminal organization Shadowspire, visits Star City. However, Diggle learns more than he bargained for about their shared time at war. Meanwhile, Oliver struggles to learn a whole new way of life. Where to Watch Episode 12 Unchained Wed, Feb 3, 2016 60 mins The team battles a formidable villain nicknamed the Calculator. Meanwhile, Nyssa makes her move; and Roy Harper returns to Star City. Where to Watch Episode 13 Sins of the Father Wed, Feb 10, 2016 60 mins Oliver receives an offer from Nyssa that is hard to refuse. Meanwhile, Thea continues to battle the blood lust; Malcolm steps in to help his daughter; and Laurel has a heart-to-heart talk with Nyssa. Where to Watch Episode 14 Code of Silence Wed, Feb 17, 2016 60 mins Oliver and team uncover HIVE's plan to take out Team Arrow once and for all. With HIVE's next attack imminent, Lance wonders if Donna is safer without him in her life. Meanwhile, with the wedding fast approaching, Oliver begins to feel guilty that he hasn't told Felicity about his son. Where to Watch Episode 15 Taken Wed, Feb 24, 2016 60 mins Oliver enlists Vixen's help to battle Darhk. She uses her magical ability to summon animal powers and gets a lock on Darhk's location. Meanwhile, Thea has a heart-to-heart talk with Malcolm. Where to Watch Episode 16 Broken Hearts Wed, Mar 23, 2016 60 mins A heartbroken Cupid returns to Star City and begins killing couples on their wedding day, which prompts Oliver and Felicity to pose as bait. Where to Watch Episode 17 Beacon of Hope Wed, Mar 30, 2016 60 mins Brie Larvan breaks out of jail and turns up at Palmer Tech threatening to kill everyone unless she gets the bio-chip that is implanted in Felicity's spine. Meanwhile, Oliver looks to a surprising ally to help rescue Felicity, Thea and Donna who are trapped in Palmer Tech with everyone else. Where to Watch Episode 18 Eleven-Fifty-Nine Wed, Apr 6, 2016 60 mins Oliver and Diggle learn that Merlyn plans to break Darhk out of prison. Meanwhile, Laurel gets a surprising offer; and Felicity has a heart-to-heart talk with Curtis. Where to Watch Episode 19 Canary Cry Wed, Apr 27, 2016 60 mins Oliver and the team struggle to come to terms with Laurel's death, especially Diggle, who is overwhelmed with guilt for choosing to believe Andy had changed. Meanwhile, Lance refuses to believe his daughter is dead and asks Nyssa to help bring her back. Where to Watch Episode 20 Genesis Wed, May 4, 2016 60 mins Oliver and Felicity look for a magical solution to defeat Darhk; vengeance-driven Diggle gets a lead on Andy's whereabouts and heads off to confront his brother; Alex takes Thea on a vacation that quickly turns into a nightmare. Where to Watch Episode 21 Monument Point Wed, May 11, 2016 60 mins Felicity realizes she needs to ask her father, Noah Kuttler, for help when Team Arrow learns what Damien Darhk's next move is going to be. Meanwhile, Noah and Oliver have a heart-to-heart talk that leaves Oliver rattled. Where to Watch Episode 22 Lost in the Flood Wed, May 18, 2016 60 mins Oliver and Diggle race to rescue Thea, while Felicity, Curtis and Noah join together to stop Darhk. Where to Watch Episode 23 Schism Wed, May 25, 2016 60 mins Season 4 ends with Oliver teaming up with a surprising force in an attempt to stop Damien Darhk and his magic once and for all. Where to Watch