With only twelve minutes left to live and his plans to stop Cicada in tatters, Eobard advises Nora to tell her parents about their partnership. Meanwhile Cicada II continues her reign of terror.
- Accidental Murder: Turns out the Gibbons' murder was completely accidental. The "killer", Vicki Bolen, is just an average suburban mom. When she touched the ATM, her powers accidentally overpowered the machine and caused it to explode. She panics and ran, completely oblivious that it killed two people, since Mayor Bellows at the time put pressure on the local media to not report meta attacks.
- Axe-Crazy: Cicada II is more unhinged than Orlin, who at least only limited himself to metas. Cicada II doesn't care who she kills and she can't be reasoned with. She refuses to accept that her parents' death was just a tragic accident (even Orlin acknowledges this) and mocks the idea of being given the cure. She cements it when she kills Orlin after he renounces his xenophobia and his actions and tries to talk her out of her current mindset.
- Break the Haughty: Cicada II's existence is one to Thawne, the Arrowverse's residential Chessmaster.Nora: You said manipulating the timeline would stop Cicada! You said you knew what you were doing!Thawne: I know what I said. I was very wrong.
- Brilliant, but Lazy: Sherloque, again! He cracks the code to Nora's diary but skips through the "boring" bits only caring about the identity of whom she's been working with. Had he done so he would've found out that despite working with Thawne, Nora has no malevolent intentions towards Team Flash.
- Broken Pedestal: A minor example, but Vicki's family wants nothing to do with her after they learn she's a meta and that she never told them.
- Brutal Honesty: While Nora still struggles, Sherloque mercilessly exposes her secret to the rest of Team Flash.
- Continuity Nod: At the Starchives, STAR Labs' warehouse of prototypes and inventions:
- Ralph comes across the faux-Cold Gun Cisco used to bluff Snart back in "Going Rogue". As it turns out, it really is a vaccuum cleaner.
- The team figures out Cicada II is Grace Gibbons from the future because she used Thawne's Time Sphere.
- Continuity Snarl: Good luck squaring the future Grace comes from where metas are a "plague" with the one seen in Legends of Tomorrow where A.R.G.U.S. has rounded them all up. Then again she does have incurable brain damage severely compromising her comprehension of reality. And as Rip Hunter has said in "Legends" the future is always in flux.
- Didn't See That Coming:
- Thawne is completely blindsided by Cicada II's existence.
- Also, this is how Vicki manages to briefly knock Cicada II on her ass, blindsiding her with a charged-up soccer ball.
- Double-Meaning Title: "Time Bomb" can refer to the nature of Vicki's powers, charging objects with energy so they explode, or Team Flash learning of Nora's partnership with Thawne, a secret that has lingered throughout the season.
- Downer Ending: Cicada II is still on the loose, Orlin is killed by Grace just when he's starting to get over his hatred of metahumans, and Barry locks Nora in the Pipeline after they find out that she's working with Eobard Thawne.
- Dramatic Irony: In the previous episode Cicada said he didn't give a damn about his legacy. This comes back to haunt him in about the most literal way possible.
- "Eureka!" Moment: When Cisco vibes the crime scene and sees Grace Gibbons' parents, and Nora remembers that in Grace's mindscape she saw herself as Cicada, they put two and two together and realize that Cicada II is Grace from the future.Cisco: Time travel sucks.
- False Reassurance: Throughout the episode Barry repeatedly stresses to Nora that Keeping Secrets Sucks and that being open and honest is the best thing — even if things seem rough at first, things get better. Unfortunately Barry is less than understanding when he finds out Nora's secret.
- Fantastic Racism: Vicki's husband and daughter are initially terrified by the revelation of Vicki being a metahuman. They eventually come around however.
- Flashback-Montage Realization: When Sherloque reveals that Nora is working with Thawne, it cuts to clips of Nora's actions and Sherloque's investigation.
- Freeze-Frame Bonus: Nora's diary entries are quite detailed, and contain many humorous tidbits (e.g. apparently Game of Thrones doesn't actually end in 2019, there's a chicken plague in 2023, etc.).
- Freudian Excuse: Grace directly witnessed her parents being blown up by a perceived meta attack.
- From Bad to Worse: Not only is Grace a Superior Successor to Orlin, she is far more malicious than Cicada ever was and is willing to murder even normal humans to achieve her mission. She fully cements this when she murders Orlin when, in the previous episode, Orlin wasn't willing to kill his niece for his crusade, proving her to be far worse than her uncle.
- Get Out!:
- Vicki tells Barry, Joe, and Nora to leave when they question her choice to tell her family or not.
- She gets told by her husband to leave after finding out she's a meta.
- Heel–Face Door-Slam: Just as Orlin was letting go of his Fantastic Racism, his own niece kills him.
- I Need a Freaking Drink: The team at the end of the episode.
- Internal Reveal:
- Team Flash finds out Nora's partnership with Thawne...because Sherloque is a big enough jerk to explain how he deduced it rather than let her do it himself, just as she's working up the courage to do it.
- Team Flash and Orlin find out that Cicada II is the future Grace Gibbons.
- Orlin also learns of Dr. Ambres' murder at the hands of Grace.
- In the Back: How Orlin meets his end.
- Jerkass: There's really, really no excuse for Sherloque Dropping the Bombshell about Nora's secret rather than let her do it. By doing so he made an already tense situation worse, by turning Team Flash against Nora. Especially since she was begging him to stop.
- Karmic Death: Orlin is killed by his own dagger, at the hands of his niece who was corrupted by his own xenophobia.
- Keeping Secrets Sucks: Discussed. While respectful of Cisco's decision, Ralph discourages Cisco from keeping Kamilla in the dark on his activities, since he cannot hide his double life forever.
- My God, What Have I Done?:
- Seeing his niece all grown up as a notorious serial killer trying to emulate him, really makes Orlin realize how far the consequences of his actions go. Unfortunately Grace just kills him.
- Earlier, Vicki accidentally got her daughter hurt.
- Noodle Incident: When Ralph is telling a story about an old boyfriend of his mom's, it ends with the random note that the guy got crushed by a falling filing cabinet.
- Police Are Useless: Cicada II is furious that the police seem to have done nothing to bring her parents' killer to justice.
- Psychic Link: It turns out that Nora going into Grace's head has resulted in her being linked to Cicada II and, whenever she is close and about to attack, Nora's eyes go black with lightning in them and she can see through Grace's eyes for a moment.
- Redemption Equals Death: Orlin completes the Heel–Face Turn he started last episode, but is killed by Grace for it.
- Redemption Rejection: Grace ignores her uncle's pleas and murders him.
- Relationship Upgrade: Cisco and Kamilla Hwang make their relationship official.
- The Reveal:
- Thawne created Nora's time cypher to get around memories being rewritten when time is rewritten.
- We find out where Team Flash keeps all their inventions they've built throughout the years, even Thawne's old Time Sphere. They have an offsite warehouse.
- Revenge: Grace came back in time to find the meta who killed her parents and kill her. She eventually transfers her feelings of revenge towards Barry.
- Self-Made Orphan: Grace murders her Parental Substitute.
- Set Right What Once Went Wrong:
- Evil version, Grace wants to prevent the spread of metahumans, which happened in her original timeline. She also wanted to restore Orlin's powers but, once she learns he took the cure willingly, murders him instead.
- Nora is the good version, trying to stop Cicada (who was never caught in her timeline and wasn't even Orlin to begin with). It isn't going too well.
- Shout-Out:
- Cisco calls the carving test on the Time Sphere "Operation Shazam!".
- Ralph hopes by bringing Kamilla to Iris' newspaper, she'll eventually get close to the team and gain powers herself, directly comparing her to Spider-Man.
- Sure, Let's Go with That: Flash and XS show up to a birthday party to protect Vicki from Cicada II, and the kids thought they were cosplayers hired to entertain them. Flash goes along with it to safely get the partygoers out of there.
- Third Line, Some Waiting: The A Plot is about Barry and the majority of the team trying to stop Grace from killing Vicki. The B Plot is about Sherloque finally deciphering all of Nora's journal. The C Plot is about Ralph giving Cisco some Unwanted Assistance with Kamilla.
- Title Drop: After John Bolen learns that his wife Vicki is metahuman, he calls her a "human time bomb".
- To Know Him, I Must Become Him: To collect evidence about Thawne, Sherloque sits on Thawne's wheelchair and wears his fake glasses. There, he finds a drive explaining the code.
- Tranquil Fury: Barry is furious when he finds out Nora's been working with Thawne. How furious? He locks her in the Pipeline. And the worst part is he doesn't even raise his voice.
- Tragic Keepsake: Cicada II proves who she is to Orlin by showing him the doll he gave her.
- Unwanted Assistance: Cisco does not want Ralph's help in getting Kamilla on the team. He wants her to have a normal life.
- Wham Episode: Grace has killed Orlin, and Team Flash now knows about Nora's connection to Thawne.
- Wham Shot:
- Thawne's old Time Sphere all the way from Season One in the middle of the woods, which is how Cicada II traveled to the past.
- A hand-written annotation on Cisco's plans for the Time Sphere: "The Timeline is malleable".
- Write Back to the Future: Invoked as a test to prove that the two Time Spheres are one and the same: carving a lightning bolt on the side of one of the spheres, which simultaneously appears on the other one.
