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 featuring pinup art by Yanick Paquette, Yuko Shimizu, Matteo Scalera, Andrea Sorrentino, Doc Shaner, Jill Thompson, and more!