John Diggle arrives in Central City with a weapon to help Barry stop the Godspeeds. Meanwhile, Allegra and Ultraviolet's new bond is put to the ultimate test, while Joe and Kristin Kramer are hunted by a former colleague of hers.
Tropes:
- 11th-Hour Ranger: Nora West-Allen finally shows up for real at the end of the episode—along with her previously unheard of brother Bart—presumably to lend a hand to Team Flash with the Godspeed war, shortly before the finale.
- All for Nothing: After everything Allegra did to reach out and save Esperanza, she ended up dying going after a remnant of Black Hole.
- Amnesiacs are Innocent: August Heart doesn't even remember his name at first.
- Artistic License – Physics: Entropy is an important part of the biological processes of life. A trap that "eliminates all entropy" would not just be a speed trap; it would be a literal death trap.
- But Now I Must Go: Diggle leaves by the end of the episode, suggesting that he's going to deal with the mysterious item he discovered at the end of Arrow.
- The Bus Came Back:
- The episode marks Diggle's first appearance in The Flash since the events of "Marathon".
- Iris also returns after being absent for the past two episodes.
- Deon appears for the first time since his last appearance in "Family Matters, Part 2".
- While Nora West-Allen has appeared in Barry's dreams lately, she actually shows up for real at the very end of the episode.
- Cliffhanger Copout: Last episode ended with Joe and Kramer sitting inside the SUV, planning their next move, car doors closed, and then the vehicle explodes. This episode reveals that Kramer noticed Adam's light moments before and the two escaped the car, apparently without opening the doors, and then hide in the forest in the split second before the explosion happened.
- Continuity Nod: Lots, courtesy of Diggle.
- Diggle brings up seeing doctors in Gotham about his headaches.
- He also brings up how he was once the Green Arrow in Ollie's place.
- John also mentions that Cisco was the one who made the entropy trap.
- Spartan's gun fires bullets filled with nanites from Ray Palmer.
- At the end of the episode, Diggle flashes back to the box he found at the end of Arrow.
- Cecile flips through Nora's journal to find clues to August Heart.
- Barry also indirectly brings up the Flashpoint timeline changes in regards to John's kids when talking about possible consequences of time travel.
- Died in Your Arms Tonight: Allegra holds Esperanza when she is dying.
- Disappears into Light: Likely due to her unique metahuman powers and associated physiology, Esperanza's death consists of her whole body turning a glowing red and gradually fading into the air.
- Dropped a Bridge on Her: Esperanza dies very abruptly.
- Enemy Civil War: The Godspeeds have essentially split into two factions. One faction wants to serve under their creator, August Heart, while the other strive to be free. The latter have traveled back in time to kill Heart before he can create his Velocity-9.
- A God Am I: Adam has shades of this due to his immortality, claiming that the world was "meant for him".
- Guest-Star Party Member: Diggle shows up to help with the Godspeed War, but has to leave by the end of the episode.
- He's Back!: For the first time since Arrow has ended, Diggle puts on the Spartan suit again.
- Hunting the Most Dangerous Game: Adam has obvious fun in hunting down Joe and Kramer in the woods.
- Identity Amnesia: Cecile and Diggle find a random guy who has memory loss. Thanks to Caitlin, it's revealed that he is August Heart.
- Immediate Sequel: This episode takes place within a few hours of the end of last episode.
- Immortality: Adam, the man hunting Kramer and Joe, is revealed to be immortal.
- Internal Reveal: Flash tells Diggle about having met his daughter from the future.
- Keet: Bart acts very excited when he appears.
- Kid from the Future: Not only does Nora return, but we get to meet Bart for the first time.
- Killed Off for Real: Esperanza dies, being mortally wounded while going after Black Hole.
- The Knights Who Say "Squee!": Chester is very excited to be working with Diggle.
- Mythology Gag: Bart, upon seeing S.T.A.R. Labs, is impressed and says that the place is "Crash", a term Bart used in Young Justice (2010).
- No Body Left Behind: Esperanza's body completely disintegrates.
- No One Could Survive That!: Adam is shocked to find the person he is ordered to hunt is Kramer, as he thought she died along with the rest of their team.
- Not-So-Well-Intentioned Extremist: While Adam mentions sending half his pays to the Native reservation he grew up in, it's obvious he is having way too much fun with what he does.
- O.O.C. Is Serious Business: Diggle immediately takes Barry to the side after the latter lashes out against Chester.
- Out of Focus: Frost and Iris, yet again. The former appears to save Diggle from one of the Godspeeds, then disappears, while the latter appears in one scene to reveal that she needs to be kept hidden for some reason.
- Play-Along Prisoner: The captured Godspeed turns out to not really be affected by the Entropy trap, as he's an artificial meta.
- Related Differently in the Adaptation: Bart here is Barry and Iris's son, not grandson as he is in the comics.
- The Reveal: Something is causing Iris to move in and out of the timelime, with Deon having to stabilize her in order not to fracture.
- Revenge Before Reason: Esperanza decides to go after her tormentors despite being just out of surgery. It ends in her death.
- Running Gag: "Nanites, courtesy of Ray Palmer" comes up yet again.
- Sensory Overload: Happens to Cecile when she uses her powers to see what is up with Diggle's headaches.
- Shout-Out: Diggle calls one of the Godspeeds Casper.
- Slave Liberation: What some of the Godspeeds are after.
- Spotting the Thread: How Kramer and Joe were able to survive, as Kramer was able to spot the light of Adam's pulse rifle.
- Suddenly Voiced: The captured Godspeed suddenly speaks in a clear manner.
- Third Line, Some Waiting: There are four plots going on in this episode:
- The main A-Plot is Barry's war against the Godspeeds.
- The secondary plot is Allegra repairing her relationship with Esperanza/Ultraviolet.
- Joe and Kramer are doing their own thing, hunting down Kramer's former comrade Adam, disconnected with everything else happening at the moment.
- Diggle is suffering from major headaches that are getting worse.
- This Is Something He's Got to Do Himself: Diggle insists on dealing with his headaches alone.
- Took a Level in Badass: Diggle notes how Team Flash has been "leveling up".
- Walk-In Chime-In: Barry tells Caitlin, "I can't leave. Not while there's a civil war in the city." Then Diggle enters and says, "Maybe I can help with that."
- Wham Line: Adam tells Kramer she actually died in the ambush along with her men. She tells Joe that he doesn't know what he's talking about, and doesn't care.
- What the Hell, Hero?: Esperanza's last words to Allegra was that she should have come with her.
- With Us or Against Us: The captured Godspeed asks Barry to help their cause, but turns hostile and attacks him when Barry refuses.
- You Don't Look Like You: In 2049 in the pre-Crisis universe, August Heart was played by Kindall Charters, while here post-Crisis in the present he's portrayed by Karan Oberoi. As Nora West-Allen has yet to meet the present-day version, it's unknown if this change was merely due to recasting Kindall Charters or if there's an actual in-universe explanation.
- You Have Outlived Your Usefulness: Why some of the Godspeeds are rebelling. They believe August Heart will simply deactivate them once his powers become permanent.
