With Barry in the speed force, Iris, Kid Flash, Joe and Vibe have taken over protecting Central City. However, when a powerful armored villain threatens to level the city if The Flash doesn't appear, Cisco makes a risky decision to break Barry out of the speed force. However, the Barry that comes out isn't the same Barry that went in.
- This episode takes place 6 months after the events of "Finish Line".
- This is the third episode of the series not to feature Tom Cavanagh.
- Since this episode takes place after "Finish Line", and since the events of "Finish Line" take place on May 24, 2017, that places this episode somewhere around November 24, 2017, over a month after this episode airs in real life.
- Wally refers to the Samuroid as Kurosawa, referencing famous Japanese film director and screenwriter, Akira Kurosawa.
- This is the first episode of the series to use a new title card.
- Shawna Baez was last seen in "Rogue Air".
- Barry's spectacular return from the Speed Force and his apparent confused state of mind while encountering Team Flash in the precinct somewhat resembles the Season 4 premiere of Smallville, entitled "Crusade". The latter episode features the return of protagonist Clark Kent from a several month long imprisonment at another plane of existence alongside some temporary personality changes.
- After Barry returns from the speed force he quotes some lines to which he relived the past and the future such as when he was trying to convince Joe that his father didnt kill his mother in the Pilot, when he travel back in time to save his mother in the episode Fastest Man Alive, when he was having a conversation with Iris before getting struck by lightening in the Pilot and in the future when he quotes some future lines when he was trying to convince a judge that he was innocent and he didnt kill anybody and another future line about needing more diapers which may reference him having kids in the future or Joe's child.
- Near the start of the episode, when the Samuroid first appears, Cisco jokingly calls him "Mifune". This is a reference to the famed Japanese actor Toshiro Mifune, well known for his work with Kurosawa (above) and also referenced in the animated series Soul Eater and Naruto.
- Cisco claims to have "made a few slight modifications" to the Speed Force bazooka, making note of his reference to the well-known phrase by Han Solo in the Star Wars franchise.
- When needing to wake Barry up, Cisco thinks of playing Poker Face by Lady Gaga, which was the same song Barry previously woke up to in Pilot.
- Cisco suggests that Barry's time may have given him the answers to "life, the universe and everything", referencing The Hitchhiker's Guide to the Galaxy.
- Caitlin follows this up by joking that the symbols Barry is drawing is his way of giving "42" to the prior question, a reference to its occurrence in The Hitchhiker's Guide to the Galaxy.
- Cisco exclaims "Great Caesar's ghost", a phrase popularly used by DC character Perry White, and "Excelsior", the catchphrase of Marvel Comics legend Stan Lee.
|The Flash season 4|
|"The Flash Reborn" • "Mixed Signals" • "Luck Be a Lady" • "Elongated Journey Into Night" • "Girls Night Out" • "When Harry Met Harry..."|
|"Therefore I Am" • "Crisis on Earth-X, Part 3" • "Don't Run" • TBA • "The Elongated Knight Rises"|