Season synopsis
Contains spoilers for this season and earlier seasons.
Five months into Oliver’s life sentence, Diaz uses the Longbow Hunters to target his allies. In Slabside, Oliver looks for a way to expose the prison’s secret Level Two facility, while Felicity and William enter witness protection and Diggle’s A.R.G.U.S. team hunts Diaz. The new Green Arrow proves to be Emiko Queen, Oliver’s half-sister, and helps the team capture Diaz. A later prison riot pits Oliver against Diaz again; Oliver wounds him and locks him in a cell, then leaves prison on a deal arranged by Laurel. The Ghost Initiative later recruits Diaz, who betrays the mission and is killed in his Slabside cell. Back in Star City, Oliver and his former teammates are deputized to work with police.
The season also follows adult William in a future Star City, where he finds Felicity’s clues, meets his hidden half-sister Mia and joins Roy, Dinah and others against Galaxy One. The group learns that the company plans to remake the city through its Archer security system; they disrupt its bomb plot, though Archer remains a threat. In the present, Oliver and Emiko investigate her mother’s murder, but Emiko is revealed as the leader of the Ninth Circle and turns its weapons against the city. Team Arrow stops the biological attack and exposes the group, but Emiko’s own allies reject her. She helps Oliver fight them, is mortally wounded, and warns him to hide Felicity and their baby. Oliver and Felicity leave Star City, settle into hiding and welcome their daughter; then Oliver accepts the Monitor’s call to help avert the coming Crisis, despite being told he will die.