In a gritty and alternate 1985, the glory days of costumed vigilantes have been brought to a close by a government crackdown. But after one of the masked veterans is brutally murdered, an investigation into the killer is initiated. The reunited heroes set out to prevent their own destruction, but in doing so they uncover a sinister plot that puts all of humanity in grave danger.

Thor is imprisoned on the other side of the universe and finds himself in a race against time to get back to Asgard to stop Ragnarok, the destruction of his home-world and the end of Asgardian civilization, at the hands of a powerful new threat, the ruthless Hela.

Fuelled by his restored faith in humanity and inspired by Superman's selfless act, Bruce Wayne and Diana Prince assemble a team of metahumans consisting of Barry Allen, Arthur Curry and Victor Stone to face the catastrophic threat of Steppenwolf and the Parademons who are on the hunt for three Mother Boxes on Earth.