Five months into his sentence, Oliver does his best to survive and keep his head down. No easy task, when he's surround by his ex-enemies, and in state of constant worry about Diaz plotting his revenge with him helpless to protect William and Felicity. Meanwhile a copycat Green Arrow has taken up the task of protecting Star City in the wake of Team Arrow's disbandment.
- Almighty Janitor: Felicity is working as barista while in witness protection from Diaz.
- Bait-and-Switch: It seems like the Lian Yu portions are detailing how the copycat Green Arrow found Oliver and trained with him in the past. It actually takes place twenty years in the future, and is William searching for Roy.
- Bathroom Brawl: A variant where Oliver is jumped in the showers by his enemies who are in prison with him.
- Beauty Is Never Tarnished: Averted, both Felicity and especially Oliver look extremely bruised after their respective run-ins with Diaz and his thugs.
- Big Damn Heroes:
- The Copycat Green Arrow saves Rene and one of his boxing students from an arms dealer who wants to kill them after they saw his wares.
- Offscreen, A.R.G.U.S. agents stop Diaz from killing Felicity and William, though he somehow manages to get away before they can arrest him.
- Briefcase Full of Money: Discussed. One criminal laments that the modern form is a tiny USB drive containing a variety of cryptocurrencies. Jason Stent isn't sorry to see the heavy, conspicuous briefcase finally got replaced.
- Broken Pedestal: Stanley is pretty disappointed (to say the least) in Oliver for letting him get beat up by Brick and Sampson, calling him a coward.
- The Bus Came Back: Several of Oliver's rogues including Brick, Bronze Tiger, and Derek Sampson who unfortunately are in Slabside Maximum Security Prison with him.
- …But He Sounds Handsome: When Dinah confronts Rene about his recent actions as Wild Dog, he initially plays dumb, but compliments the man who did them.
- Call-Back:
- As Felicity gives the hozen to William, she mentions that Oliver gave it to Thea when he returned from his 5 years away, as seen in the pilot.
- The new Green Arrow's actions in this episode are one big Call-Back to Oliver's first mission as the Hood in the pilot. He steals Jason Stent's cryptocurrency and donates the money to small business owners in the Glades, much like how Oliver stole the money Adam Hunt embezzled and returned it to his victims. And much like Hunt, Stent's name too is crossed off a List. The conversation between Rene and Dinah about the new Green Arrow's actions mirrors the similar conversation Laurel and Joanna had back in the pilot.
- Chronic Hero Syndrome:
- Oliver's plan is to keep his head down, not make trouble, and hopefully get his sentence reduced. But in the end, he just can't help himself especially after Sampson and Brick beat up Stanley just to try to provoke him into attacking them to get him in trouble with the guards. And also Diaz had found Felicity and William anyway.
- Rene can't resist putting his Wild Dog costume on again after he is saved by the Green Arrow coypcat.
- Cliffhanger Copout: Diaz finds Felicity and William, and threatens he's going to make them hurt. Next we see, Felicity is inexplicably visiting Oliver and saying A.R.G.U.S. rescued them offscreen, in what looks for all the world like the setup for a reveal that Diaz is using William to force her to do something. But no, they really were just rescued offscreen, with normal human Diaz somehow escaping a full A.R.G.U.S. team with the power of "Who knows?"
- Cool Teacher: Now that his days as Wild Dog are over, Rene is teaching self defense to his daughter Zoe and other kids from the Glades.
- Easily Forgiven: Averted, despite having put aside her revenge, Dinah is understandably still pretty pissed at Black Siren.
- Flash Forward: The scenes with the stranger and Roy on Lian Yu are revealed to be this at the end of the episode when the stranger is revealed to be an older William.
- Foreshadowing: Oliver keeps having nightmares about Diaz killing Felicity and William. While Diaz doesn't kill them, he does comes dangerously close to doing so.
- Four Lines, All Waiting:
- Oliver trying to survive life in Slabside.
- Felicity and William trying to adjust to life without Oliver.
- Team Arrow trying to cope with a copycat Green Arrow.
- An older William trying to contact a mysterious hooded figure... whom turns out to be Roy.
- Hoist by His Own Petard: Oliver tells Sampson and Brick they should have killed him when they had the chance.
- Hope Bringer: Rene claims that the kids in the Glades started to have hope again after the Copycat Green Arrow appeared.
- I Warned You: Oliver constantly tells Stanley not to talk to him, so the other prisoners won't use him. After getting beaten by Sampson and Brick for his trouble, Stanley tells Oliver he needed his protection because he knows he won't last behind bars, and that he was wrongfully convinced of murder.
- I Will Wait for You: Invoked by Felicity when she tells Oliver that she will always wait for him, no matter how long he ends up staying in jail for, but she's done living her life in hiding.
- Kick the Dog: Poor Oliver is jumped in the showers, sucker punched, and then told by another inmate that Diaz found Felicity and has killed her.
- The Lopsided Arm of the Law: Dinah bitterly notes that Agent Watson is still keeping eyes on Star City to ensure the former Team Arrow members don't put their masks back on, even though she's no closer to finding Diaz and putting him away, something which is emphasized when he comes dangerously close to killing Felicity and William.
- Miscarriage of Justice: Stanley, the inmate who goes to Oliver for help, has been wrongfully convicted of murder.
- Nightmare Sequence: The episode begins with Diaz hunting down Felicity and William. Turns out it's just Oliver having a nightmare fueled by his anxieties about being unable to protect them.
- Older Than They Look: According to show runner Beth Schwartz, the Flash Forward takes place twenty years in the future (2038), which means Roy ages remarkably gracefully.
- Once a Season: Much like the first four season premieres, and the start of the series' 100th episode, this episode starts with a POV shot of someone running through the woods...except that this time it's William rather than Oliver.
- Parallel Conflict Sequence: Oliver's fight in the prison showers is intercut with scenes of Felicity fighting Diaz in her and William's witness protection house.
- Pariah Prisoner: Oliver's identity as the Green Arrow makes him this. Many of the prisoners are in Slabside because of Oliver. They dislike him, but aren't crazy enough to outright fight him, so he spends most of his time alone with the rest of the room glaring at him menacingly.
- Properly Paranoid: Everyone is right to worry about the possibility of Diaz coming after Felicity and William; even after moving away and establishing new identities, he still ends up doing exactly that, and they barely escape with their lives.
- Protagonist Title: The eponymous Inmate 4587 is Oliver himself.
- Protector Behind Bars: Oliver is trying to keep his head down, but he hasn't lost his protective streak towards his friends and family. When they're threatened, Oliver's plans to keep a low profile go out the window.
- Put on a Bus: William, who is being sent to boarding school in Cambridge to keep him safe while Felicity stays in Star City to find Diaz.
- Revenge:
- Brick, Bronze Tiger, and Derek Sampson are more than ready to pay Oliver back for putting them behind bars.
- Diaz wanted to take his revenge on Oliver by killing Felicity and William while he's locked up in Slabside. Luckily ARGUS agents show up to stop him at the last minute.
- Screw the Rules, I'm Doing What's Right!:
- Rene believes Team Arrow should ally with the new Green Arrow despite the deal Oliver made.
- Likewise, Oliver wipes the tally marks and beats the prisoners that hassled him and Stanley despite the guard telling him to stand down.
- Senseless Sacrifice: Diaz almost killing Felicity and William underscores how Oliver cutting a deal with Agent Watson that ended with him in Slabside was a very poor decision on his part.
- Sympathetic Inspector Antagonist: Dinah tells Rene that she is going to arrest him next time she catches him as Wild Dog again. Seems a little harsh at first, but considering the amount of pressure she is under due to the deal they did with Watson, it's understandable.
- Tally Marks on the Prison Wall: Oliver literally marks the days in tally using a piece of chalk. The tallies indicate he's been in Slabside a little over five months.
- Took a Level in Badass: Felicity actually manages to fight Diaz off long enough for A.R.G.U.S. to arrive.
- Tranquil Fury: Oliver doesn't even raise his voice once when he beats up Brick and the henchman of Diaz who told him Felicity is dead. But it's clear that he is not going to take anymore shit from anybody.
- Unexplained Recovery: It's a mystery what Bronze Tiger is doing in Slabside since on the show he was was last seen in A.R.G.U.S. custody and then killed off in the comics set between Seasons Two and Three, which seemed to be canon since he's been absent until now. The most likely explanation is Flashpoint.
- Welcome to Corneria: The guard assigned to Oliver greets him every morning with the same "Morning 4587. Beautiful day."
- Wham Line: Two big ones in the very last seconds of the episode.Stranger: [holds up the hozen] My father is Oliver Queen.
Roy: ...William? - Wham Shot:
- Felicity walking into Slabside, after Oliver believes Diaz killed her.
- The copycat Green Arrow crossing a name off a list.
- A visibly older Roy is on Lian Yu.
- You Are in Command Now:
- Earth-2 Laurel is now Star City's District Attorney.
- Dinah is SCPD's police captain now.
- Curtis is now head of the R&D department at A.R.G.U.S.
- You Are Number 6: A particularly slimy guard makes a point of greeting Oliver every morning as 4587.
