The trial began. Barry Allen stood accused of murdering Eobard Thawne in cold blood. Peter Farley's defense was that Barry hadn't intended on breaking the Reverse-Flash's neck, that he had done so by accident, in a panic to stop the villain from replicating the very same murderous actions that had already claimed the life of Iris Allen, Barry's wife and soul mate.
As far as soul mates go, Barry had no idea...
In matters of time travel, the physical body becomes an approximation of itself the moment an individual breaches their own linear dimension; the only thing that truly undertakes the journey is the consciousness of the individual.
Iris came from the future. She was a child when her parents sent her to Barry's time. She already knew everything that would happen, but her specific age was chosen so that she would still have a chance of participating in her own decisions, so that she would grow into the role of Iris West and Iris Allen of her own accord.
The other individual who participated in these events, the mad magician of science, Abra Kadabra, took on a perverted view and understanding of this same principle, believing that he could finally achieve his life's dream by ensuring that Iris survived her own death and returned in time to prove Barry's innocence.
He had become a foe of Barry's well after the career and legacy of the most famous Flash had become history, believing that his intuitive knowledge of the Speed Force somehow made a mockery of Abra's efforts to master nature. If you ask me, the man was first and foremost a headcase.
But that's villainy for you. In this case, it actually worked in everyone's favor. By inserting himself into Iris's efforts to transplant her consciousness back into Barry's time, he gave her the body she needed and the exact moment she needed to appear, at the end of the trial, when all seemed lost, when all the court needed was an expert witness. Who better than Iris Allen?
The press had a field day with the ruling, but what was anyone to do about it? If they believed that Barry Allen, that the Flash was the fastest man alive, they had to accept the reality of time travel, and therefore everything Iris might have to say about it, how Eobard Thawne couldn't possibly be dead, that there were very real reasons to believe that he would be back, that above all else, Barry was innocent of the charges, thanks to sophisticated technology that in the future proved his innocence...
Actually, none of that really matters. The trial brought out the worst in everyone because it had to draw out greater truths, reveal that there was so much more going on than anyone realized, most of all what Barry Allen himself knew.
He was happy to see Iris, beyond relieved to see her alive, but he sensed that she was holding something back. She was reluctant, at first, but then she agreed that they had all experienced extraordinary events, and that she owed it to Barry to be as honest as possible.
So she told him. She told him about the Crisis, how he would sacrifice his life, so soon after learning how precious it really was, to save the universe, by running faster than he ever had before. He would be consumed by his own speed.
The only thing she didn't tell him was that this wouldn't be the end. She told me in later years that she decided to make this incredible concession to the integrity of the timeline because she owed it to Barry, for the inspiration he provided to her own history, to mine, to my children's, to the tradition of justice and superheroes, everything that we can sometimes take for granted.
My name is Wally West, and I'm the fasted man alive. Sometimes there are things more important than that.