In the aftermath of Heroes in Crisis, Wally West is at his lowest point, responsible for the deaths of his friends and fellow heroes and imprisoned. To make matters worse, his former wife Linda Park still doesn't remember their life together or their kids. Wally is ready to give up on life when he is swept away by multiversal guardian Tempus Fuginaut, as he is the only hero fast enough to prevent the destruction of the multiverse.
The story received an epilogue in The Flash #750 anniversary issue, while the collected edition includes material from the unpublished Generation Zero one-shot that leads into the events of Dark Nights: Death Metal.
Flash Forward provides examples of:
- The Ace: Wally is established as being, in addition to the fastest of the Flash Family in his own universe, the fastest being in all of existence.
- Ascended to a Higher Plane of Existence: In the final issue, Wally sits on the Mobius Chair, becoming something more than just Wally and the Chair due to some of Dr. Manhattan's power being imbued in it.
- The Atoner: Wally reluctantly aids Tempus Fuginaut to atone for the pain and death he caused at Sanctuary.
- Bittersweet Ending: Iris and Jai are rescued from the dark world and reunited with Linda Park-West, her memory now restored. However, Wally West is now trapped in the Mobius Chair, souped up on the power of Dr. Manhattan and he has ominous plans.
- The Bus Came Back: The end of issue 2 features the return of Jai and Irey West.
- The Corruption: Dark Matter from the Dark Multiverse is leaking into the greater Multiverse and risks corroding the whole thing. Calvin Ellis says touching it feels like touching death itself.
- Death Seeker: Wally is willing to let the other prisoners beat him to death before Tempus Fuginaut recruits him.
- Evil Counterpart: The JL-Dead, the vampire incarnation of the Justice League that Wally fights in issue 3. They've all been turned evil by their Earth's Batman, who turned them into vampires.
- The Hero: Wally, but he re-learns how to fill the role. After Heroes in Crisis, he's initially more than willing to let others kill him and only reluctantly helps Tempus Fuginaut, but over time manages to move on from his grief and regains the joy and spark that made him an optimistic hero.
- Hope Spot: Issue 4 ended with Wally reunited with his children at long last. The following issue revealed that the world he found them on is the world he created through his own fears of losing his children, meaning that to destroy that world meant that he would have to lose his children again.
- Let's You and Him Fight: In issue 2 as Wally seeks out the incursion of dark matter on Calvin Ellis' Earth he's briefly attacked by the other heroes of that world as an apparent assailant of their friend before Cal explains the situation. He leaves and finds the source but encounters the heroes of Earth-8 also in search of cause of the erosion of their reality. Presuming Wally's the problem while explicitly dismissing any consideration otherwise due to time constraints they immediately attack him.
- Nice Job Breaking It, Hero: Wally angrily asks Tempus Fuginaut why he was chosen to fight the Dark Matter. Tempus tells him that Wally has become "unstuck" from reality. This presents a problem because the worlds in the Dark Multiverse are formed from people's desires and fears, and the world created from Wally's fear of losing his family is just as unstuck as he is and it's essentially "clogging the drain" making it so that the Dark Matter keeps leaking into the Multiverse.
- Replacement Goldfish: In the third issue, Wally briefly teams up with a vampire-hunting Roy Harper, who he sees as a chance at closure regarding his Roy's death.
- Sequel Series: Serves as a follow-up to Heroes in Crisis due to Wally's actions in that series resulting in his status quo here, as well as one to Dark Nights: Metal due to the darkness from the Dark Multiverse being the primary threat.
- Wham Shot: Issue 2, Irey & Jai West are still alive, and have been trapped in the Dark Multiverse.