The latest addition to what is turning into a massive film, Oppenheimer, is Matthias Schweighöfer, star of Army of the Dead and Army of Thieves. He joins Cillian Murphy, Emily Blunt, Matt Damon, Robert Downey Jr., Florence Pugh, Josh Hartnett, Dane DeHaan, Rami Malek, Kenneth Branagh, David Krumholtz, Alden Ehrenreich, and more. Murphy will play J. Robert Oppenheimer, the scientist who played a vital role in the development of the atomic bomb. The film is based on the book American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer by Kai Bird and the late Martin J. Sherwin. Oppenheimer will open on July 21, 2023.