While trying to decipher The Monitor's mission, Oliver returns to Starling City where he encounters familiar faces; Mia and William's team clash with a new foe.
Oliver, John, Laurel and Tatsu seek out an important person within The Monitor's plan; Connor has a heart-to-heart with his brother.
Reunited with his sister, Oliver and Thea find themselves searching through a familiar maze of catacombs; John and Lyla partner on a mission.
When a mysterious new Deathstroke appears in Star City, Oliver and Team Arrow insist on taking down this villain themselves; reeling from the loss of one of its own, the future Team Arrow figures out a new way to stop JJ.
Upon learning the key to opposing The Monitor, Oliver and team return to Russia on a mission to gather the necessary materials; Diggle reunites with a figure from his past.
Oliver is faced with a life-or-death situation after being double-crossed by Lyla; Laurel has an opportunity to make amends.
Oliver's mission takes him to Lian Yu, where he tries to ignore the repercussions of the looming crisis until he receives help from an old friend; a united Team Arrow faces a recognizable villain.
Stuck in the Vanishing Point, the Paragons search for a way to escape; Oliver reveals that he has become something else; the origin stories for The Monitor and Anti-Monitor are revealed.
In the year 2040, Mia Queen has everything she ever wanted -- until Laurel and Dinah show up.