Smart kid builds a nuclear bomb. This was intelligently done. It would be really easy to screw up a movie with this kind of plot. It’s been done countless times. Sure, the “steal the plutonium” scene was a little unbelievable, but it did work – the movie didn’t make any “leaps of faith” with respect to plot development, it let the intelligence of the characters move the plot along. (one thing though, if you smoke inside, it still smells for hours afterwards)