What is the plot of man of tomorrow?

Quick Answer
Man of Tomorrow follows Superman and Lex Luthor as they reluctantly team up to battle the superintelligent villain Brainiac.
Explanation
Man of Tomorrow is an upcoming American superhero film set in the DC Universe. Written and directed by James Gunn, it serves as the fourth film in the DCU and a direct sequel to Superman (2025). The story centers on Clark Kent, played by David Corenswet, and Lex Luthor, portrayed by Nicholas Hoult, who are forced to join forces to confront a larger threat: the superintelligent alien entity Brainiac, whose presence threatens Earth. While the main focus is on the reluctant partnership of the two iconic characters, the film also features a supporting ensemble that includes Rachel Brosnahan, Skyler Gisondo, Isabela Merced, Frank Grillo, María Gabriela de Faría, Sara Sampaio, and Milly Alcock, with additional roles by Lars Eidinger (Brainiac), Aaron Pierre, and Xolo Maridueña. Production is led by James Gunn and Peter Safran of DC Studios, who aim to deepen the narrative stakes of the DC Universe while exploring the complex dynamics between its most famed heroes and villains.