- "Barry isn't going to Hell. But like all runners must eventually, he's reached his finish line. His race is over."
- —Speed Force to Team Flash
- This episode aired on May 23, 2017, which was the date on which Savitar originally killed Iris.
- Savitar mentions DeVoe as he recalls his memory in S.T.A.R. Labs. This is a reference to Clifford DeVoe, a villain known as The Thinker. This is the second time a reference on DeVoe was made, the first being in "" by Abra Kadabra. Savitar stated that it "hadn't happened yet", foreshadowing the appearance of The Thinker in Season 4, where he is the main antagonist.
- This reference would first become significant in the episode Season 4 episode "", when new ally Ralph Dibny makes a reference to having been hired by 'DeVoe'; Barry is only aware of the significance of the name due to Savitar and Abra Kadabra having also mentioned the name.
- Savitar mentioning DeVoe is quite similar to when Ra's al Ghul mentions Damien Darhk in the Season 3 finale of ; both Ra's al Ghul and Savitar are the cult-leading, god-like main villains for the third seasons of both The Flash and Arrow while DeVoe and Darhk would go on to become the main antagonists of the fourth seasons in unusual way: Darhk is the first magical villain of Arrow and DeVoe the first non-speedster villain of The Flash. Both villains also reveal themselves in the fourth season premieres.
- Cisco refers to Savitar as "Two-Face" after being rescued by Gypsy. This is a tongue-in-cheek reference to the comics villain Harvey Dent aka Two-Face, an antagonist of Batman who also has severe scarring on half of his face.
- The story of his family that Barry talked to Savitar about could be a reference to the beginning of the animated DC movie Justice League: Flashpoint Paradox. This storyline was also the catalyst for Season 3.
- A quote from Mark Twain appears on H.R.'s tombstone.
- Cisco asks Wally to "reverse the polarity on the neutron flow", referencing a catchphrase of the Third Doctor in Doctor Who; "reverse the polarity of the neutron flow"
- Hunter Zolomon's current form has been named as Black Flash by Savitar.
- Hunter's death is similar to that of Amaya's in "" in Season 2 of .
- The scene where Savitar is vibrating his hand while preparing to kill Cisco and telling him that he will die "the same way twice" refers to the latter's death in the erased timeline in "".
- Savitar is killed the same way that The Rival was killed in ""; The Rival was shot in the back by Joe while trying to attack Barry from behind, and Savitar was shot in the back by Iris when trying to do the same to Barry.
- The Speed Force lightning storm above Central City is a reference to a similar storm that appeared in the first issue of the 2016 Flash relaunch comic that infused several citizens with the Speed Force. It's now known that the one seen in the episode has similar abilities to potentially create new meta-humans.
- This episode is set after the Season 2 finale of , "", given that Black Flash appeared in that episode to kill Eobard Thawne, and is killed in this episode.
- This is the third time that Barry went into the Speed force, the first time being in the episode "" and the second time in "".
- This is the last episode of the series to use the original title card used since Season 1.
- In the previous episode, H.R.'s last words to Cisco are "'Til next time" and he salutes the latter after putting on his hat. However in this episode, the flashback shows it was changed to "'Til the next one" and H.R. slightly tips his hat.
|"" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • "" • " "|