Oliver struggles to balance his new role as Mayor with the Arrow's solo work on the streets in the absence of his team, as new crime boss Tobias Church comes to Star City. In the past, Oliver arrives in Russia and is entangled with the Bratva crime syndicate.
The Green Arrow's attempts to train a team of new recruits leads only to frustration, while Mayor Queen launches a new medical initiative that attracts attention from a rag-cloaked assailant. Diggle finds himself in over his head on a mission, and in the past Oliver tries to prove himself to the Bratva.
The new team has trust issues after Wild Dog defies Oliver's orders and attacks a drug dealer, Garret Runnels, undermining a bigger operation. But Runnels' exposure to a chemical vat leaves him unable to feel pain, and the Green Arrow must find a way to stop him. Meanwhile, Thea inadvertently embarrasses the Mayor when a TV reporter turns on her.
Against Felicity's better judgment Oliver joins Lyla on a secret mission to break Diggle out of a military prison. When Tobias Church launches an attack on the city, the new recruits decide to take him on by themselves. Meanwhile, Rory must decide if he can return to the team and work with Felicity.
Oliver finds himself targeted by Tobias Church after the crime boss learns his secret identity, and turns to an old friend for help. The team tries to rescue their captive teammate, while in the past Oliver finds that some members of the Bratva may not be as accepting of him as he had hoped.
Prometheus calls out Oliver by dropping seemingly random bodies in Star City, which soon point the team to the Arrow's own dark past -- threatening to create a schism among the new recruits. Thea suspects that Quentin may be back on the bottle, and in the past Oliver finally meets Konstantin Kovar face-to-face.
Team Arrow tries to catch Star City's newest Vigilante, a killer who is targeting criminals and leaving them dead. Thea tries to help Lance when he comes to her with an unsettling secret, and in the past Konstantin Kovar tells Oliver that he does not know which side he is really on.
Held captive by the Dominators inside a shared dream, Oliver and the others awaken to an ideal life where the Queen's Gambit never went down and Laurel never died -- and where Diggle fights to protect the city as a vigilante called the Hood. Back on Earth, Flash and Supergirl join Team Arrow to retrieve technology needed to mount a resistance.
Oliver goes after Prometheus after he attacks Curtis, but the enemy proves time and again that he is always one step ahead of the Green Arrow. New clues make the team suspect that Prometheus has a connection to Oliver's ruthless first year back in Starling City.
Oliver and Felicity's joy at the apparently miraculous return of Laurel Lance is short-lived, as she is caught up in a new ploy by Prometheus. In prison, Diggle depends on legal help from District Attorney Adrian Chase as he finds himself in a new fight for his life.
Oliver, Curtis, and Rene head to Hub City to try and recruit a new Black Canary in Tina Boland, a former CCPD detective out to avenge the murder of her partner. Felicity attempts to hack the NSA to help free Diggle, and in the past Oliver receives an offer of help from Talia al Ghul in his quest to take down Kovar.
Oliver and the team travel to Russia, where his old friend Anatoly agrees to help them find and stop General Walker -- but only if Oliver helps him first. Rene helps a recovering Lance prep for an interview with the press, and in the past Talia presses Oliver to return home.
Oliver must solve a new problem in his role as Mayor after City Hall is attacked by a lone gunman, thrusting Team Arrow into a very personal conflict over gun control -- and dredging up painful memories of Rene's past.
The villainous sirens China White, Cupid, and Liza Warner break out of prison and return to Star City, searching for a stash of cash -- and a little payback. Thea and Felicity discover the extent of intel that Susan Williams has on Oliver, and in the past Oliver defends Anatoly from an assassin.
Oliver faces possible impeachment as Mayor after the cover-up of Detective Malone's death is exposed, and must decide whether to allow someone else to take the fall for his actions. Convinced that the Mayor is corrupt, Vigilante targets Oliver directly -- and Thea decides to play politics to help her brother.
After discovering the identity of Prometheus Oliver struggles to keep up with his adversary, who has kidnapped Susan Williams and insists on keeping up appearances in his day job. Felicity agrees to do some work for Helix in order to solidify her access to their advanced (and not entirely legal) resources.
Prometheus brutally tortures a captive Oliver, demanding that he admit his deepest secret. Five years ago in Russia Oliver and Anatoly discover that Konstantin Kovar is plotting to overthrow the Russian government, while Oliver tries to honor a promise.
Oliver disbands the team in the wake of his confrontation with Chase and, with no other options, turns to Anatoly and the Bratva to eliminate his enemy. As Felicity works with Helix to try and expose Prometheus's identity, Diggle tries to pull his friend back from the brink.
An unsuccessful attempt to capture Prometheus sends Felicity to her new allies at Helix, who target a suspect in pursuit of their own agenda. And when Helix asks Felicity for more help in their cause, she finds herself standing against ARGUS -- and her own team.
An attack on the bunker leaves Oliver and Felicity trapped together beneath the surface, where they work through some personal issues while fighting to survive.
A mysterious delivery to the Mayor's office implicates Oliver's father in an unsolved murder, forcing him and Thea to consider the paths they are on. Rene debates whether his daughter will be better off without him, and in the past Oliver and Anatoly return to Lian Yu.
The team's attempt to catch its breath and celebrate Oliver's birthday is cut short when Chase acquires a new ally in Black Siren, who helps to pick off Team Arrow one by one in order to draw Oliver into a final confrontation. In the past, Oliver is surprised to learn that he has been followed back to Lian Yu.
Oliver returns to Lian Yu and assembles a team of tenuous allies -- including Slade Wilson, Merlyn, Nyssa, and Digger Harkness -- to confront Chase and rescue his loved ones, who are being held captive on the island. Five years in the past, Oliver must survive a final confrontation with Kovar.
