As a new cyber criminal stalks Star City, Nyssa finally begins to plan her revenge against Merlyn.
- Adaptational Name Change: The Calculator's heroic, wheelchair-bound, computer-genius daughter in the comics is named Wendy (yes, the Canon Immigrant from the Superfriends). Here, it's Felicity Smoak.
- Archnemesis Dad: The Calculator, Felicity's newest enemy, turns out to be her father. However, Felicity doesn't know this until the next episode.
- Big Damn Heroes: Team Arrow is surrounded by six armed mercenaries. Oliver arrives to take them all down in under 10 seconds.
- Blackmail: The Calculator found out who Roy Harper was and is forcing him to commit burglaries under the threat of exposing him to the police.
- The Bus Came Back:
- Roy comes back for the first time this season.
- Curtis comes back having not been seen in a while.
- Nyssa comes back having not been seen since Sara's revival.
- Katana also comes back having not been seen since the Season Three finale.
- Shado returns (albeit as a hallucination) for the first time since Season Two.
- Call-Back:
- Merlyn brings up John Constantine's actions to save Sara's soul.
- Thea mentions how Malcolm offered her a pedophile to kill to sate her bloodlust.
- In the flashbacks, Oliver, upon seeing the hallucination of Shado, assumes its her sister Mei, whom he met in Hong Kong last season.
- Roy mentions how most of Oliver's plans involve shooting him; a reference to the two occasions in Season Two when this happened.
- Code Name: Felicity annoys Team Arrow by using their codenames excessively because she loves them saying "Overwatch" back to her. However she thinks "The Calculator" is lame.
- Composite Character: Felicity is revealed to be one. She has the name of a minor Firestorm character and the traits of Wendy from the Superfriends after becoming a Canon Immigrant to the Teen Titans comics.
- Continuity Snarl: Malcolm explained that Sara Lance no longer has blood lust because John Constantine fully restored her. The episode after Sara's full resurrection shows that she still suffers from it. That being said, Sara's case doesn't seem to be nearly as bad as Thea's. That, and Malcolm has lied before.
- The Cracker: The Calculator, as is his nature.
- Dead Person Conversation: Oliver and Shado in the flashbacks.
- Deal with the Devil: Oliver considers making one with Darhk to save Thea, but is talked out of it. Then Nyssa turns up at the end of the episode offering her own.
- Dramatic Irony: Felicity meets her dad, unaware he's the superhacker she spent the entire episode dueling.
- Dramatic Unmask: The Green Arrow unmasks the burglar to reveal Roy Harper.
- Dueling Hackers: Overwatch versus The Calculator.
- Easily Forgiven: Malcom once again gives off this vibe, as basically everybody treats him as normal to have around by now.
- Electric Torture: Involving Reiter and a hand-cranked generator.
- Enemy Civil War: Followers of Nyssa, the original Heir to the Demon, help her escape so she can topple The Usurper Malcolm Merlyn.
- Evil Counterpart: The Calculator to Felicity, in addition to being an Archnemesis Dad. He's got the computer skills, and the pop culture references.
- Evil vs. Evil: Neither Nyssa nor Malcom are on the side of the angels.
- Face-Revealing Turn: Tatsu as the woman praying at the Japanese temple.
- Faking the Dead: Realising that Roy has a camera contact lens watching everything he sees, Oliver shoots him with a tranquilizer arrow to make it look like he's killed him, then drags his body into the Faraday Cage-shielded Arrow Bunker to remove it.
- Foil: The Shado hallucination that Oliver sees is the kind and patient mentor he remembers, as opposed to the spiteful hallucination witnessed by Slade during his Mirakuru-induced insanity.
- Foreshadowing:
- Laurel suggests that the Roy that Oliver encountered was someone who could make themselves look like Roy, pointing out that it's hardly the craziest thing they've encountered. Next season Oliver encounters the Human Target who indeed has this ability.
- Shado won't be the last ghost to appear on Lian Yu.
- Forgotten Fallen Friend: Nyssa doesn't mention Sara's murder at all in this episode. She only mentions that Merlyn is an "usurper". Then again the motives of her followers are likely different from the likes of Laurel or Oliver.
- Hacker Duel: Overwatch vs Calculator.
- Helpful Hallucination: Oliver is being tortured by Reiter when someone arrows him in the chest. It turns out to be Shado, who after this Commercial Break Cliffhanger reveals herself to be still dead but here to help Oliver get past his guilt issues. Oliver wakes up later in the prison cell, holding the Fantasy Keepsake she gave him.
- Hidden Agenda Villain: It has yet to be revealed why The Calculator wants to destroy Star City.
- Hidden Badass: Curtis gets to show off fighting skills against Roy, but can't quite get the upper hand.
- Incurable Cough of Death: Thea's Blood Lust condition worsens.
- Insistent Terminology: Felicity refuses to refer to the Calculator as such, seeing it as a stupid name.
- Internal Reveal:
- Taina learns that Flashback!Oliver killed her brother.
- Oliver learns about how Darhk's "magic death touch thingie" temporarily cured Thea.
- The Internet Is for Cats: The Calculator gets hold of a device that Felicity worries could be used to destroy the Internet. He denies the charge, pointing out that a) the Internet is where he works, and b) he's addicted to funny cat videos.
- It's All My Fault: Lampshaded so often with our hero that Dig dubs Oliver "Guilt Arrow".
- I Want My Beloved to Be Happy: Roy can't stay in Star City because there's too much chance he'll be recognised. Thea is in tears as she talks of how she would just be happy knowing Roy was somewhere having a normal life with a family. Then Roy wishes he could have lived his life over again so that would happen with her.
- Jail Bake: A variation when Nyssa is brought a pepper with a small knife inside. It's all she needs to cut the guard's throat and take his sword.
- Knight Templar Parent: For the very first time, Malcom manages to avert being this, knowing it would just drive Thea away. He even convinces Oliver to respect Thea's decision to die rather than become a killer or let her brother make a Deal with the Devil.
- Le Parkour: Oliver and the burglar engage in this during their chase, which serves as foreshadowing for The Reveal that he's Roy Harper who had these skills.
- Let's You and Him Fight: Roy has to fight Team Arrow because he has a camera in his eye watching everything he does, so can't afford to go to his friends for help for fear of exposing his connection to them. Nyssa briefly spars with Tatsu before convincing her to take another option.
- Locked Out of the Loop: It appears that Nyssa doesn't know that Sara had her soul restored.
- Match Cut: A variation when Felicity's wheelchair rolls right into the flashback-dream of Oliver meditating with Ghost!Shado.
- Meaningful Echo: Amanda Waller's "The only way out is through" is repeated by Ghost!Shado.
- Morality Chain: Ghost!Shado convinces Oliver to tell the truth about Vlad's death to Taiana.
- Multi Tasked Conversation: A captive Nyssa is refusing to eat until the woman bringing her a pepper urges her to try it.Mesi Natifah: The pepper came from the garden. The garden grows strong even in your absence. Please try a bite.
- Mythology Gag:
- Amertek is mentioned as one of the few viable businesses still in Star City. In the main DC Universe, Amertek Industries was the defense contractor that used to employ John Henry Irons.
- Roy mentions he started a new life in Hub City before the Calculator blackmailed him. Hub City is the traditional home of The Question.
- Laurel brings up the possibility that the Roy that returned is just a copy/fake. In Young Justice (2010), Roy is subjected to cloning blues, and the first one seen is actually the clone.
- There's a Cadmus Labs. Cadmus is an important project in the DC Universe.
- Thea wishes that Roy will have a child and wife someday. In the comics, Roy is married to Cheshire and they have a daughter named Lian (not connected to the not-so Deserted Island). However, if he follows this route in the show, he likely won't find the happiness Thea hopes he will.
- No Honor Among Thieves: Due to Merlyn's prolonged absences from Nanda Parbat, Nyssa is able to lead a coup from inside the League itself, even though it's members are suppose to be one hundred percent loyal to the current Ra's Al-Ghul without question.
- Not So Stoic: During this episode, Reiter is shown losing his cool for the very first time while torturing Oliver.
- Oblivious to Love: Flashback-Oliver denies to Ghost!Shado that he has fallen in love with Taiana.
- Oh, Crap!: Oliver when he finds out Darhk's wife is running against him in the election.
- Open Mouth, Insert Foot: Curtis tells Felicity to "break a leg" when she's about to give her presentation, while Dennis says to put her best foot forward. Given that she's in a wheelchair, Felicity is not amused.
- Or Was It a Dream?: The Fantasy Keepsake version when Oliver wakes up with the engraved stone that Shado gave him.
- Outrun the Fireball: Arsenal does this when he blows up Calculator's device.
- The Plot Reaper: Averted with Katana surviving this episode, in contrast to Deadshot and Amanda Waller whose fates were sealed by
Executive Meddling due to the upcoming Suicide Squad (2016) film. - Related in the Adaptation: The Calculator becomes Felicity Smoak's father. In the comics, they are unrelated and the guy is mainly a Birds of Prey villain.
- The Reveal: The Calculator turns out to be Felicity's father.
- Right Under Their Noses: The Calculator is revealed to be sitting next to Oliver at Felicity's presentation at Palmer Technologies.
- Sadistic Choice: Oliver can let his sister die due to her bloodlust or kill Malcolm for Nyssa and obtain the cure.
- Sarcastic Confession: Alex asks how Oliver got to campaign HQ so quickly. Oliver tells him: A secret elevator in the building. Which would be absurd, he came through the side door.
- Snark-to-Snark Combat: Curtis is working on his revolutionary new Power Cell when Roy enters to steal it.Roy: I don't want to hurt you.Curtis: I don't want you to hurt me, either.Roy: Well, I'm going to need to take that.Curtis: Oh, I think you might have to hurt me, then.
- So Happy Together: Their shared grief over Thea causes Oliver to reconcile with Malcolm (including a shot of them shaking hands which becomes particularly ironic given what happens in the next episode). Then Nyssa turns up with a deal that will drive the two men into conflict.
- Spotting the Thread: Felicity notes that something is different about Roy's eye, from which she quickly extrapolates that he's wearing some kind of tech that has something to do with what he's doing.
- Trailers Always Spoil:
- Showrunner Wendy Mericle confirmed in an interview long before the episode aired that there would be a connection between Felicity and the Calculator (pretty much spoiling the reveal that the Calculator is Felicity's father).
- Roy's return, not to mention the circumstances of his involvement with the Calculator, were spoiled by promos and interviews.
- Unaccustomed as I Am to Public Speaking...: Curtis notices the difference between the assertive Felicity zipping fearlessly around his office because she's saving the city, and the clumsy Felicity who lacks the confidence to give the presentation on the Power Cell to the Palmer Technologies board of directors.
- Unholy Matrimony: Ruvé Adams is not just cheering her supervillain husband on from the sidelines; she's now running for Mayor in opposition to Oliver.
- Unplanned Manual Detonation: Roy has to detonate the C4 with an arrow, then Outrun the Fireball.
- Vision Quest: While being tortured, Flashback-Oliver has a vision of Shado, once again appearing as his mentor as in Season One, this time as a Spirit Advisor instead of an archery instructor.
- Wham Line: Felicity, at the end, to The Calculator when meeting him in person:Felicity: Oh my God...Dad?
- Wound That Will Not Heal: A variation; the wound from where the last Ra's stabbed her reappears whenever Thea's lifeforce weakens.
- You Are Better Than You Think You Are: Curtis gives Felicity the pep talk to make a self-confident speech as CEO.
