The explosive storyline from BATMAN #21-22 and THE FLASH #21-22 is collected in a trade paperback edition!

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!

Author/Artist: Joshua Williamson / Tom King / Howard Porter / Jason Fabok
Publisher: DC Comics
Page Count: 104pp
Size: 7 x 10
Notes: softcover, full color, deluxe edition
Date of Publication: June 19, 2019
ISBN: 978-1401294298