- For other uses of "King Shark", see King Shark (disambiguation).
- "We're gonna need a bigger Flash."
- —Cisco, after finding out about King Shark
Wells, Cisco, and Barry agree not to discuss what happened on Earth Two for fear of repercussions. While everyone tries to move on, the humanoid shark-monster that Wells stopped, known as "King Shark," escapes A.R.G.U.S. custody and heads for Central City to kill the Flash. John Diggle and Lyla Michaels arrive to warn Barry, which prompts him to look for King Shark and put a stop to him for good. Barry teams up with Diggle, Lyla, and the rest of A.R.G.U.S. to track King Shark, but he shows up at Barry's home looking for the Flash, tracking Barry's electrical field. A.R.G.U.S. arrives and forces King Shark to retreat. The teams attempt to trick King Shark into a trap, but the bait does not work. Barry forces King Shark to chase him out on the water and, when he is far enough, creates an electrified underwater cyclone that subdues King Shark and allows A.R.G.U.S. to imprison him again. Later, Barry vows to open a breach back to Earth Two to stop Zoom. Back on Earth Two, Zoom's masked prisoner watches in horror as Zoom drops Jay's corpse on the floor. Zoom then removes his mask, revealing his face to resemble "Jay".
- There are numerous references to the movie Jaws in this episode. The shark is called Bruce, the same name as the mechanical shark in Jaws. Cisco says "Just when you thought it was safe to go back to the suburbs" referencing the Jaws 2 tagline “Just when you thought it was safe to go back in the water". They also say "We’re gonna need a bigger Flash" referencing the line "We're gonna need a bigger boat" in the original Jaws. Cisco also says he should be "playing Quint" referencing a character in the original movie. Wells then points out that Quint dies in the film.
- This episode marks the only appearance of John Diggle without Oliver Queen.
- This is the first of two episodes of the Arrowverse to feature Lyla Michaels without Oliver Queen, with the other being "Infantino Street".
- Nautilus Labs is a reference to the Nautilus from Jules Verne's 20,000 Leagues Under the Sea.
- A reference to the metal promethium is made, used in the comics to create Cyborg's body and Deathstroke's sword.
- The "Shay Lamden" identity is new for the show. In the comics King Shark is Nanaue, the half-human son of a shark deity.
- ↑ 'Vixen', Old 'Oliver' & 'King Shark' Feature In Descriptions For ARROW, LEGENDS OF TOMORROW, & THE FLASH - Comic Book Movie
|The Flash season 2|
|"The Man Who Saved Central City" • "Flash of Two Worlds" • "Family of Rogues" • "The Fury of Firestorm" • "The Darkness and the Light" • "Enter Zoom" • "Gorilla Warfare" • "Legends of Today" • "Running to Stand Still" • "Potential Energy" • "The Reverse-Flash Returns" • "Fast Lane" • "Welcome to Earth-2" • "Escape from Earth-2" • "King Shark" • "Trajectory" • "Flash Back" • "Versus Zoom" • "Back to Normal" • "Rupture" • "The Runaway Dinosaur" • "Invincible" • "The Race of His Life"|