Jeff Lemire! Michael Walsh! DC Comics and Dark Horse Comics team up for the ultimate superhero crossover event! A strange man arrives simultaneously on Black Hammer Farm and in Metropolis and both worlds are warped as Starro attacks! Batman, Green Lantern, Flash, Wonder Woman, Superman, and more crossover with Golden Gail, Colonel Weird and the rest of the Black Hammer gang! Collects Black Hammer/Justice League: Hammer of Justice #1–#5 and features pinup art by Yanick Paquette, Yuko Shimizu, Matteo Scalera, Andrea Sorrentino, Evan ''Doc'' Shaner, Jill Thompson, and more!