Cillian Murphy stars as the "Father of the Atomic Bomb" in a stacked ensemble that includes Emily Blunt, Matt Damon, Robert Downey Jr. and Florence Pugh.

Both a probing character study and a sweeping account of history, Christopher Nolan's Oppenheimer is a brainy, brawny thriller about the man who led the Manhattan Project to build the bomb that ended World War II. To dispense with the inevitable weapon of mass destruction metaphors, it's more slow-burn than explosive. But perhaps the most surprising element of this audacious epic is that the scramble for atomic armament ends up being secondary to the scathing depiction of political gamesmanship, as one of the most brilliant scientific minds of the 20th century is vilified for voicing learned opinions that go against America's arms-race thinking.

Chiseling Kai Bird and Martin J. Sherman's whopping, definitive biography, American Prometheus: The Triumph and Tragedy of J. Robert Oppenheimer, from 700-plus pages into a three-hour screenplay, Nolan hasn't entirely streamlined the dense plot.

It can feel like a talky thicket of scenes in which men in midcentury business attire stand around in offices and labs having animated discussions about quantum mechanics, which at times lack the elucidation to afford non-physicists much access. It's a relief when, about an hour in, one of the ever-expanding lineup of theoreticians plops marbles into glass containers to demonstrate the difference between uranium and plutonium as fusion bomb components.

But there's a method to Nolan's approach, which becomes increasingly apparent as the two separate Washington hearings laced throughout the narrative intersect in the foreground and occupy the riveting final hour. And the emotionally affecting decision to close with an earlier private conversation between Cillian Murphy's J. Robert Oppenheimer and Albert Einstein (Tom Conti) elegantly brings it all back to the personal views of two men looking at their branch of science from different perspectives.