"ZA" is, in fact, a word in the Scrabble dictionary and is the most-played word containing the letter Z (the only 2-letter word to contain that letter) in Scrabble tournaments.
Just like the previous episodes, this episode references previous seasons:
- The clothes that the inspectors, Barry, and Iris were changed into is similar to what happened in The One with the Nineties (2021), in which Joe, Frost, Caitlin, and Iris were wearing clothes that were popular in different points in time caused by Deon Owens' powers.
- The inspection is very similar to when the CCDBS did a radiation inspection when they noticed a radiation leak in S.T.A.R. Labs, which was caused by Eobard Thawne, prompting the inspectors to shut down S.T.A.R. Labs in Armageddon, Part 2 (2021).
- The scene where everything returned back to normal in a flash of light due to time travel is very similar to what happened in Armageddon, Part 4 (2021) when Barry travel back to the present to change the timeline in which a flash of light removed all of his friends that were being tortured by Despero.
- When Barry laments everything that happened at S.T.A.R. Labs, flashbacks of previous episodes from previous seasons are shown: a) Marlize DeVoe fighting Iris which took place in Lose Yourself (2018) b) Ramsey Rosso/Bloodwork leading an army of Blood Brothers in The Last Temptation of Barry Allen, Pt. 2 (2019) c) An army of Godspeeds invading S.T.A.R. Labs in Enemy at the Gates (2021) d) A zombified Mitch Romero that was created by Ramsey Rosso/Bloodwork exploded right in front of Barry and Frost in Dead Man Running (2019).
This is the first episode of the series to not feature Jon Cor (Mark Blaine) after he was promoted to a series regular.
In the year 2123 just after the mysterious hooded figure set off the intruder alert alarm at the door to the Weapons Vault in the Flash Museum at S.T.A.R. Labs then creates and jumps into a portal and disappears, the camera zooms in to show an inspection certificate on the wall next to Weapons Vault door, showing the date of the last inspection as having been "5 April 2023," one hundred years before. This was the date that this episode first aired.