Watch Justice League Dark (2017) : Full Movies Free Streaming Online When innocent civilians begin committing unthinkable crimes across Metropolis, Gotham City and beyond, Batman must call upon mystical counterparts to eradicate this demonic threat to the planet; enter Justice League Dark. This team of Dark Arts specialists must unravel the mystery of Earth's supernatural plague and contend with the rising, powerful villainous forces behind the siege—before it's too late for all of mankind.