Billy Batson will have the opportunity to see if his title of "World's Most Powerful Mortal" is well deserved. Dr Sivana and Mr Mind are back, along with several monsters, having formed the Monster Society of Evil. Black Adam, who wants his revenge and takes Billy's powers, agrees to leave this society, but his point of view on mortals could well change here. However, to fight against all these powerful enemies, Billy may need some help... from the family !