It opens with Oppenheimer walking through the desert and climbing up a tower of some sort to inspect an object at the top. Matt Damon voiceover talking to Cillian. He calls him a "womaniser" among other things and questions his qualifications. Cillian snaps back by saying "brilliance makes up for a lot" (or something like that) and asks him why he isn't a general yet and Damon responds that they're going to make him one for what they're about to do. Then the trailer jumps through several quick shots and characters. We see Oppenheimer walking and talking with who I assume is Einstein. Oppenheimer asks what happens if "the reaction doesn't stop" or something along those lines. We hear someone talk about how they're building a facility as we get a wide shot of Los Alamos and a shot of Oppenheimer and Kitty driving inside in a jeep. There's several shots of a bomb being assembled as pieces are fit together to form a metal globe. We see Josh Peck with what looks like big welding glasses on. There's a shot of someone wearing a silver looking facemask of some kind. There's also several shots of flames and what can only be described as neutrons spinning around an atom or something moving at a very high speed. The trailer builds as we see shots of timers and countdowns as it's clear it's building to the bomb going off and several voiceovers of people questioning what's going to happen and then a final cut to black as the trailer ends with a final black and white shot of Downey saying "Well, we know what happened don't we?".

Incredible trailer. If the one released online is even half as good then it's easily going to convince people to see the film.