WARNING: This article contains a major spoiler for The Flash #50 by Joshua Williamson, Howard Porter and Hi-Fi, on sale now.
This week's The Flash #50 marked the surprise return of a prominent pre-Flashpoint speedster, a fan favorite who simply could not exist in the New 52 universe. Though Wally West ultimately failed to rescue his child Jai and Irey by breaking the Speed Force, he inadvertently freed another member of the Flash family -- Bart Allen, the young speedster best known as Impulse.
While the reveal is certain to excite longtime readers, fans who came to The Flash more recently may be at a loss -- after all, even before the New 52 reboot, it's been some time since we've seen that costume in action. So who is Impulse?
My Name Is Bart Allen
Debuting in 1994's The Flash #92 by Mark Waid and Mike Wieringo, Bart Allen is the grandson of Barry and Iris Allen, born and raised in 31st century. Before Barry sacrificed his life to save the multiverse in Crisis on Infinite Earths, he and Iris briefly enjoyed a happily-ever-after in the far future, Iris's home era. They had superpowered children, Don and Dawn Allen, known as the Tornado Twins, but unfortunately, they met their fates during an invasion by the Dominators. Bart is Don's son with Melanie Thawne, a descendant of Eobard, the Reverse Flash.
That's a lot, and we're just getting started!
Bart's metabolism aged him incredibly rapidly, such that he physically appeared to be twelve years old when chronologically he was only two -- to compensate, he was raised in a virtual reality world that could keep pace with the world as he experienced it. As such, he has very little concept of consequence and reacts purely on impulse -- hence the name.
Iris shuttled Bart back to our present, where Wally was able to stabilize Bart's aging. Impulse's apprenticeship to the Flash was contentious, though, and soon Bart found himself living with and learning from Max Mercury, the Zen Guru of Speed.
Bart had his own series, Impulse, which ran 90 issues, and was also a member of Young Justice before changing his superhero name to Kid Flash and joining the Teen Titans.
Bart was even the Flash for a little while! When the DC Universe jumped "One Year Later" after the events of Infinite Crisis, a slightly aged-up Bart donned the red and gold to star in The Flash: The Fastest Man Alive. That series lasted only 13 issues, ending with Bart being beaten to death by the Rogues. He was later resurrected, once again as the teenage Kid Flash, in Final Crisis: Legion of Three Worlds.