WARNING! THIS ARTICLE CONTAINS SPOILERS FOR THE SEASON 2 FINALE OF CW’S THE FLASH, ALONG WITH OTHER EPISODES IN THE ARROWVERSE! READ AT YOUR OWN RISK!
It’s now been a week since The Flash Season 2 finale aired, and it got me thinking about all the alternate timelines created on The Flash. Let’s take a quick look at all the timeline on The Flash and the impacts they have had on the larger Arrowverse:
Original timeline, which we never actually see on the show. In this timeline, Barry Allen and Iris West are married. Barry Allen is given the powers of The Flash by the activation of the S.T.A.R. Labs particle accelerator in 2020.
Alternate Timeline 1
Eobard Thawne travels back in time from the mid-22nd century to the year 2024. With the help of Green Arrow, The Atom, and Hawkgirl, The Flash fights Reverse-Flash, and the two speedsters disappear in an explosion of light. Presumably this is an alternate timeline from the Original Timeline, and is also never seen on the show. Since the affected events of this timeline occur in the future, they have no discernible impact on our knowledge of the Arrowverse.
Known changes from the Original Timeline include:
- The battle between The Flash and Reverse-Flash likely never occurred in the Original Timeline.
- Presumably, The Flash never disappeared in the Original Timeline.
Alternate Timeline 2
Failing to defeat The Flash in 2024, Eobard Thawne travels back in time to the year 2000 to kill Barry Allen as a child. The Flash follows him, preventing Barry’s death, but Reverse-Flash kills Barry’s mom instead, creating Alternate Timeline 2. Upon attempting to return to his own time, Eobard discovers he has lost his connection to the Speed Force and is stranded in the 21st century. He kills Harrison Wells and his wife, and impersonates Dr. Wells, speeding up the creation of the particle accelerator explosion and creating The Flash earlier in the timeline.
Alternate Timeline 2 is the timeline seen in episodes 1.01 – 1.15 of The Flash. Known changes from Alternate Timeline 1 include:
- Barry Allen is raised by Joe West when his father is framed for the murder of his mother.
- Eobard Thawne murders Harrison Wells and takes his place in the timeline.
- S.T.A.R. Labs builds the particle accelerator seven years earlier than in the previous timelines, creating multiple metahumans who would not otherwise have been created.
- All of the events of The Flash, and probably the entire Arrowverse. At the very least, every interaction Barry Allen has with the Arrowverse.
Alternate Timeline 3
Mark Mardon creates a tidal wave to destroy Central City. While running really fast to stop the tidal wave, The Flash travels back in time one day. Knowing how events originally played out, Barry does things differently than before, creating alternate Timeline 3.
Alternate Timeline 3 is the timeline seen in episodes 1.16 – 1.23 of The Flash. Known changes from Alternate Timeline 2 include:
- Mark Mardon is captured by The Flash before he can cause any real damage, including the tidal wave that threatens Central City.
- Without the stress of Joe’s kidnapping, Iris never realizes her feelings for Barry or learns that he is The Flash.
- Cisco never investigates Dr. Wells, doesn’t discover he is Eobard Thawne, and is not killed by Reverse-Flash.
- All of the events of The Flash following episode 1.15 possibly never occurred in Alternate Timeline 2. It is unknown if events in the rest of the Arrowverse were affected.
Alternate Timeline 3a
During the final fight between The Flash and Reverse-Flash, Eddie Thawne kills himself, preventing Eobard Thawne from ever being born. Strangely enough, instead of creating Alternate Timeline 4, Eobard Thawne vanishes from the present, but his actions of the past remain. Barry’s mother was still murdered by Reverse-Flash and his father is still in jail. This creates a time paradox singularity, which creates multiple holes between Earth 1 and Earth 2.
Also, prior to the final fight between The Flash and Reverse-Flash, Barry travels back in time to the moment of his mother’s death, intending to stop Thawne from killing her. Ultimately, he decides to do nothing, and the timeline remains the same.
Alternate Timeline 3a is the timeline seen in episodes 1.16 – 2.08 of The Flash and episode 4.08 of Arrow. There appear to be no changes to the timeline, thus this series of events is not technically a new timeline.
Alternate Timeline 4
While attempting to stop immortal psychopath Vandal Savage, Arrow, Hawkgirl, and Hawkman are killed in a massive wave of destruction. The Flash attempts to outrun the wave, but instead travels back in time twenty-four hours. With his knowledge of the future, Barry enables the team to kill Vandal Savage, creating a new timeline.
Alternate Timeline 4 is the timeline seen in episode 4.08 and beyond of Arrow and episodes 2.08 – 2.17 of The Flash. Known changes from Alternate Timeline 3 include:
- Oliver never runs a DNA test on William as Barry already knows the result. Consequently, Felicity never finds out that Oliver has a son.
- Cisco helps Kendra discover her inner-Hawkgirl, enabling the team to develop a way to kill Savage.
- Oliver brings the entire team to the final fight with Vandal Savage, providing a distraction which allows Arrow and The Flash to destroy Savage.
- Oliver, Hawkgirl, Hawkman, and Barry survive the battle with Vandal Savage.
Alternate Timeline 5
Barry decides that the only way to stop Zoom is to go back in time and ask Dr. Wells, AKA Eobard Thawne/Reverse-Flash, how to increase his speed. After traveling back in time, he prevents Hartley Rathaway’s escape from S.T.A.R. Labs, creating an alternate timeline.
Alternate Timeline 5 is the timeline seen in episodes 2.18 – 2.23 of The Flash. Known changes from Alternate Timeline 4 include:
- Team Flash learns that speedsters have the ability to travel through time earlier than they originally did.
- Central City is plagued by a time wraith, which is looking for future Barry.
- Team Flash of the past begins working with Hartley Rathaway to develop a way to defeat time wraiths, and Rathaway becomes a hero instead of a villain.
- Most of the events from episodes 1.11 and 1.12 were negated. It is unknown if any other events of the Arrowverse were affected.
Alternate Timeline 6
After defeating Zoom, Barry tells Iris he needs some time before he will be ready to jump into a relationship with her. He travels back in time to the year 2000 and prevents Reverse-Flash from killing his mother. It is unknown how this will affect the overall timeline of the Arrowverse, but the disappearance of the 2015 time-traveling Flash suggests that Nora Allen’s survival may have entirely reset the timeline and prevented Barry from becoming The Flash. Because of Barry’s interactions with Vixen and Team Arrow, the entire Arrowverse is likely affected in unpredictable ways, probably resetting to either the Original Timeline or Alternate Timeline 1.
While talking about alternate timelines I have not yet mentioned Legends of Tomorrow. The actions of Rip Hunter and his team have undoubtedly created many an alternate timeline, but that is an article for another day.
In creating this list, I have also not taken into account alternate timelines from Time Remnants. It is unknown exactly how many time remnants Zoom created, so I decided it was easier to just not worry about them.