The roster of A-list actors to star in Christopher Nolan's upcoming directorial venture Oppenheimer keeps getting longer, as Penny Dreadful actor Josh Hartnett joins the team. This film is Nolan's first since he walked away from Warner Bros. and as far as the casting is concerned, the man is not pulling any punches, like always. However, it is not yet clear which role Hartnett will be bringing to life.

After almost a two-decade wait, the famed director is finally getting to work with Hartnett. Initially, Nolan had approached the Pearl Harbour and Black Hawk Down actor for the role of the Caped Crusader in Batman Begins, which is hardly surprising given his strong performance in both films. After it did not work out, the part went to Christian Bale, who did more than enough justice to the role.

The already star-studded cast of Oppenheimer consists of a host of talented actors, with Cillian' Tommy Shelby' Murphy in the eponymous role. The cast also includes Golden Globe-winner Emily Blunt, who will be playing the role of Katherine Vissering Oppenheimer, wife of J. Robert Oppenheimer. Florence Pugh stars as Jean Tatlock, who had an affair with Oppenheimer and was a member of the Community Party of the United States. The list goes on with Matt Damon, Robert Downey Jr., and Rami Malek. Benny Safdie will play Edward Teller, yet another significant brain of the Manhattan Project, who is considered the father of the hydrogen bomb.

Oppenheimer tells the story of the 'father of the atomic bomb' and draws its inspiration from the 2005 Pulitzer Prize-winning book 'American Prometheus: The Triumph of J. Robert Oppenheimer', by Kai Bird and Martin J. Sherwin. Apart from writing and directing the biopic, Nolan will also be producing it along with Emma Thomas and Atlas Entertainment's Charles Roven. The film is set to release on July 21, 2023, roughly two weeks before the anniversary of the nuclear strike on Hiroshima.

Apart from Oppenheimer, Hartnett is also set to star in several upcoming films, like Guy Ritchie's spy action comedy film Operation Fortune: Ruse de Guerre, where he will be joining the likes of Jason Statham and Aubrey Plaza. In addition to this, he is also set to star in James Franco's upcoming directorial venture, the indie film The Long Home. However, it is not clear when the latter will release, as the film has been stuck in development since 2015.