"All roads lead…to darkness. In the devastating and epic conclusion to DC’s cataclysmic event series, heroes from across the universe make their final charge into the unknown to battle the forces of the Dark Multiverse! Space and time, dreams and nightmares, all will collide—and what is left at the end will leave the DC Universe irrevocably changed!" -DC Comics
Here is a complete master checklist of all the covers to Batman's Dark Nights: Metal #6.