Barry Allen has never been able to slow down -- and he's still not fast enough. Not fast enough to save his Mother, without the speed to be there for Iris, and not quick enough to save Pietro Maximoff from himself.
Barry has undergone much of the standard Flash origins, the death of his mother at the hands of the Reverse Flash, his life with the West family, and the lab accident that would transform him into the one and only scarlet speedster, The Flash.
In this iteration, The Flash is close friends with Pietro Maximoff, a fellow officer at CCPD who revealed his mutancy to Barry after deducing the fellow officer was, in fact, The Flash. Inspired by Barry's then-month of antics as Central City's red streak. The badge was hardly enough to contain Pietro's ambition, and he would join The Flash on the scene as the hero Quicksilver.
With the tutelage of the previous Flash, Jay Garrick, the speedsters scarlet and silver would battle all manner of metahumans, mutants, and madcap scientists across Central City. From Captains Cold and Boomerang to the dastardly pair of Weather Wizard and Whirlwind, Barry and Pietro kept the city safe and were, for a time, awarded with idyllic lives. Pietro rising in the ranks of CCPD, and Barry finding love with his childhood friend Iris West.
Things would change with the re-emergence of the Reverse Flash. Faster than Quicksilver and Flash put together, it would take weeks of training and the combined efforts of all three of Central City's speedsters and the local branch of STAR Labs to defeat the man in yellow, and send him back in the timestream from whence he came. But Barry's speed now sat differently in his body; as fast as he and Pietro had become in their training, Barry was only getting faster.
The faster Barry became, the harder and harder it was to slow down. Seconds long quips around the office water cooler stretched into minutes and hours; even Pietro was falling behind. At a point, the other speedster might as well have been as slow as anyone else.
Pietro grew envious of Barry's speed, and sought out the X-Men for further, specialized training as a mutant. During this time, Barry became Central City's sole protector, with the occasional assist from Garrick or other heroes. His work as The Flash was the one thing keeping him sane, zipping to punch bank robbers and save cats from trees in-between the beats of conversations wherever he could, sparing his undivided attention almost exclusively for Iris. As long as it took for Barry to understand even her simplest words, he hung on them, an anchor to a less tumultuous time in his life.
Everything changed on Pietro's last mission with the X-Men, learning of his true parentage: he was the spawn of Magneto, leader of the Brotherhood of Mutants. Believing Magneto could lead him to the speed he desired, Pietro turned on the X-Men, becoming a zealous believer in Magneto's cause. In his father's world, Pietro could be the fastest mutant alive.
Despite Pietro's dreams, his hopes were dashed by Barry's intervention. Alongside the X-Men, The Flash defeated The Brotherhood, putting Magneto behind bars as Pietro disappeared to the four winds.
Barry would grow faster still, now able to approach lightspeed, he had all the time in the world; yet, still, less and less for Iris. Barry abandoned his job at the CCPD at dedicated himself to full time crimefighting, never slowing for an instant, zipping across the the country to solve problems wherever he was needed.
Achieving such phenomenal speeds, Barry learned of the Speed Force, as well as its self-appointed expert and guardian, Professor Zoom. Under Zoom, Barry would break the barriers of light and time, becoming one of Earth's most powerful heroes, and facing off once more against Eobard Thawne, this time within the confines of the speedforce. Barry emerged victorious, but his challenges were far from over.
Zoom had another pupil. The Rival, a black clad speedster spoken of only in rumor. The Flash would clash with The Rival in his now worldwide sprints, in sparks of black and red too fast for even Superman to follow -- The Rival was, in all Barry's years, the only man to ever truly keep up with him. Everything fell to the wayside in Barry's life. There was no Justice League, no X-Men, no Iris: only the threat of The Rival, approaching over the horizon.
In their final battle, The Rival unmasked himself: he was Pietro. Using a combination of the experimental drug Velocity 9, his personal notes on Barry's accident, a mysterious benefactor, and the blood of countless other speedsters, Pietro had finally achieved the speed he so desired.
In their pitched battle, Pietro was able to leverage his newfound command over the Speedforce to sever Barry's connection to it -- before the other speedster disappeared, without a trace.
Barry now finds himself on Mojoworld, significantly slower than he should be, relying exclusively on his biological speed. For the first time in his ten years as The Flash, Barry has been forced to slow down and reflect. Through each of Mojo's trials, barry reflects on what he's lost in his pursuit of the speedforce: his career, his allies, his closest friend, and the love of his life.