In last week’s Batman #21, Tom King and Jason Fabok began to unravel a mystery that’s plagued the DC Universe for over a year. After a bloody smiley face button ends up inexplicably embedded into the wall of the Batcave, Batman and The Flash realize that they’re being “watched” by powerful forces that have rewritten their memories and the fabric of reality itself. The two heroes have teamed up to get to the bottom of the situation and restore the rightful order of the universe, but after the Reverse Flash took the Dark Knight down in a brutal fight, will The Flash have to solve the mystery on his own?

Check out the Comics Beat’s exclusive preview of The Flash #21 after the jump.

Writer: Joshua Williamson Artist: Howard Porter Colorist: Hi-Fi Letterer: Steve Wands “THE BUTTON” part two! The cataclysmic events of DC UNIVERSE: REBIRTH #1 continue here! The Dark Knight and The Fastest Man Alive, the two greatest detectives on any world, unite to explore the mystery behind a certain blood-stained smiley button embedded in the Batcave wall. What starts as a simple investigation turns deadly when the secrets of the button prove irresistible to an unwelcome third party—and it’s not who anyone suspects! It’s a mystery woven through time, and the ticking clock starts here!