: Believing Kid Flash might be linked to a series of Speed Force murders, Barry chases the bratty teen across the globe.
: Barry Allen and Bruce Wayne team up to investigate a blood-stained smiley face button found in the Batcave.
In the 2013 New 52 continuity, The Flash #21 gave fans a long-awaited "race of the century" between Barry Allen and the impulsive teenager Bart Allen, also known as Kid Flash. Flash 21
: In this timeline, Wally West has become a "war general," sending speedster copies of himself on suicide missions to defeat the villain Eclipso.
In more recent stories (2025), The Flash #21 has explored even weirder cosmic horror. : Believing Kid Flash might be linked to
: The story offers tantalizing glimpses into Bart's origin in the 31st century.
: It highlights the unique bond between Batman and Flash, grounded in their shared love for forensic science. When Barry Met Bart: The New 52 : In this timeline, Wally West has become
One of the most famous versions of The Flash #21 was published in 2017 as the second part of " The Button ". This storyline directly connected the world of the Flash to the mysterious Watchmen universe.