Frost is accused of a crime committed by an ice-themed villain and sets out to prove her innocence, while Barry and Iris invite the Speed Force to stay with them and Joe butts heads with the mysterious Kristen Kramer.
Tropes:
- Accent Upon The Wrong Syllable: For no discernable reason, Barry says hexaGONal instead of the more standard hexAGonal.
- Affably Evil: Mark Blaine/Chillblaine, much like his predecessor Leonard Snart before his move to Legends of Tomorrow, is a chatty and charming guy who just happens to also be a criminal.
- Apologetic Attacker: For obvious reasons, Joe feels horrible about arresting Caitlin.
- The Atoner: Frost decides to give herself up for the crimes she did commit when she and Caitlin were one person.
- Atrocious Alias: Mark Blaine gives himself the name "Chillblaine", which Flash reacts to saying that he's glad Cisco wasn't there to hear him call himself that.
- Attacking Through Yourself: Frost stabs a piece of ice through herself to incapacitate Mark.
- Bar Brawl: Frost gets into one with several patrons at Mark's bar when they decide to try and bring her in for the reward money.
- Beam-O-War: Mark and Frost match their cold streams against each other.
- Big Damn Heroes: Mark knocks out one thug who tries to stab Frost from behind.
- Bittersweet Ending: Frost is absolved of the murder charge placed against her, but because she's still wanted for her other crimes, she decides the best thing to do is turn herself in and face the consequences for her actions.
- Call-Back: To all of Killer Frost's crimes.
- Chekhov's Gunman: The friendly bartender Frost meets with early on in the episode is revealed to be the killer who framed her.
- Clear My Name: Frost attempts to prove that she's innocent.
- Continuity Cavalcade: Frost's previous crimes from Season 3 as "Killer Frost" are run down at the start of the episode: Accosting an acolyte of Savitar, kidnapping Julian, attempting to kill Tracy Brand, and kidnapping Cecile.
- Dating Catwoman: Frost and Chillblaine being enemies yet somewhat enamored for one another.
- Deliberate Injury Gambit: When Mark has her in a hold and is about to stab her with an ice blade they're fighting over, Frost intentionally elongates it and runs herself through with it to stab him too, counting on her Healing Factor to save her.
- Didn't Think This Through: Frost just going to a bar when there is a warrant out for her arrest was bound to cause trouble.
- Eating the Eye Candy: Frost does this when Mark takes his shirt off after the fight at the bar.
- Empowered Badass Normal: Mark is a splendid hand-to-hand fighter who gains cryogenic powers.
- "Eureka!" Moment: When Caitlin talks her down from busting her out, Frost realizes it was Mark who framed her.
- Exact Words: Joe promises Kramer that Caitlin and Frost are not the same person. He fails to mention that they are separated split personalites, however.
- Eye Scream: Mark briefly covers Frost's eyes with ice to blind her.
- Foil:
- Mark/Chillblaine to Frost. Both develop ice powers, but whereas Frost's are natural, Chillblaine's are artificial. She's snarky but well-meaning, while he's friendly but dangerous.
- Kramer to Joe. Both are people in law enforcement who want to do good for the people, but Kramer is judgmental and won't hesitate to resort to extreme measures to apprehend criminals, while Joe is more reasonable and wants to gather all the evidence before casting suspicions.
- Frame-Up: Frost is framed for killing the Ivo Labs driver.
- Green-Eyed Monster: Mark is jealous of Frost's powers and thinks she can do much more with them, hence copying them for himself.
- Grievous Bottley Harm: Mark breaks a bottle on one of the thugs attacking Frost.
- Healing Factor: Exploited. Despite copying Frost's powers, Chillblaine doesn't have her Meta healing. Which she uses to stab herself through an ice attack while impaling him as well.
- I Lied: Frost breaks her promise to stay put and Allegra lies about Frost working out.
- Impaled with Extreme Prejudice: A non-fatal variant with Chillblaine, as the Flash quickly patches him up after Frost stabs him with an ice weapon through her own body.
- Insistent Terminology: When Barry refers to Frost as such, Kramer insists that she’s ‘Killer’ Frost.
- Inspector Javert: Kramer is (seemingly) just trying to do the right thing with attempting to arrest Frost, with no ulterior motives.
- Irony: Cecile mentioning how she was held hostage by Frost during her stint as a villain. Four years later, she sees her as a friend and her client.
- Literally Shattered Lives: What happened to the unfortunate Ivo Labs driver whose van was attacked by Chillblaine.
- Mad Scientist: Mark was fired from Ivo Labs because they deemed his experiments inhumane.
- Miranda Rights: Joe reads them to Caitlin when he arrests her.
- Mr. Fanservice: After Frost fights off guys at the bar she visits, Mark removes his shirt, causing her to become briefly flustered.
- Mythology Gag:
- Frost stabs Chillblaine with an icicle, similar to how his comic book counterpart died (courtesy of Captain Cold), although he survives here thanks to Barry's timely arrival.
- Chillblaine in the comics was also associated with an ice based villainess, the Golden Glider.
- Oh, Crap!: Frost when she realizes everyone in the bar is about to jump her for the reward money.
- Pals with Jesus: Barry with the Speed Force by the end of the episode.
- Pet the Dog: Despite Kramer's hard-ass personality, the Speed Force notes that she holds a great deal of respect for Barry.
- Power Copying: Mark uses his technology to scan Frost and replicate her ice powers.
- Power Incontinence: Barry's powers go out of whack several times throughout the episode. He claims that it's because the Speed Force is overloading him, though it might be more psychological. At the end of the episode, he gets the hang of it.
- Shout-Out:
- When Chester gets excited about being called to his first crime scene, Frost calls him "Peralta".
- When arriving at the crime scene, Chester says "Holy Baby Grogu!".
- Chester compares Team Flash to the Power Rangers, even calling the Speed Force their Zordon (though the more apt comparison would be that the Speed Force is the Morphin Grid).
- He also refers to Kramer announcing the bounty on Frost's head as a move from John Wick: Chapter 3 – Parabellum.
- Spider-Sense: The Speed Force reveals they're able to detect when Barry is feeling distress and will happily comes to his aid. Even if he doesn't ask for it.
- Stalker with a Crush: Mark reveals he's been tracking Frost for years, seeing a kindred spirit with her due to his obsession with ice. During their brawl, it almost looks like they are about to kiss each other at several points.
- Start of Darkness: Mark's was when he fell through ice as a child in a skiing accident, died and was resuscitated fifteen minutes later, becoming obsessed with the substance ever since.
- Story-Breaker Power: Chester points out that the Speed Force is omniscient, so she knows the answer to everything. Barry however refuses to exploit this.
- Surprisingly Realistic Outcome:
- The Speed Force wearing the face of Barry's dead mom was bound to become awkward at some point.
- Despite having redeemed herself, the charges against Frost were never dropped, so she is legally still a fugitive.
- Frost has never worn a mask at any point during her superhero or villain career. So facial recognition software is easily able to match her to Caitlin.
- They Called Me Mad!: This is part of Mark/Chillblaine's motive — during his time at Ivo Labs, he was apparently doing experiments which his employers considered "inhuman". He's been in hiding since then, as what he did was apparently enough to earn a life sentence at Iron Heights, while his work was confiscated by his former employers.
- Tragic Keepsake: Allegra is now wearing Nash's clothes in honor of him.
- Tricked-Out Gloves: Chillblaine uses high-tech gauntlets to imitate Frost's powers.
- Unwanted Assistance: Barry tells the Speed Force to leave him alone after insisting on helping him and only making him more annoyed.
- What the Hell, Hero?: Joe is not happy with Kramer for arresting Caitlin solely based on one anonymous tip.
- You Fight Like a Cow: Or like a boy, as Frost taunts Mark.
- You Wouldn't Shoot Me: Mark laughs off Frost's threat to kill him as Caitlin wouldn't be happy about that.
