The men are rescued through the efforts of Dave Karnes (Michael Shannon), a senior accountant with Deloitte & Touche in Connecticut, and a devout ex-marine, who feels called by the attacks to defend his country. He confides in his minister, gets a high-and-tight haircut, and walks into Ground Zero, identifying himself as an active marine. He'd rather give up his name than his rank; when asked for a shorter handle than "Staff Sergeant Karnes," he says, "You can call me Staff Sergeant." Stone doesn't get the full nutty flavor of this exchange (Karnes's eccentricity may itself explain why he undertook this mission at all), but the director doesn't seem very committed to the religioso aspect introduced by Karnes, either. Karnes's actions are based in fact, but there's something ectoplasmic about the character that Stone doesn't quite know how to integrate into the straightforward power-of-familial-love context. Shannon starts giving off a psycho-killer buzz and Stone drops him after he's served his purpose.
It's as if Stone anticipated being accused of making an Oliver Stone movie, of exploiting this sensitive material that we fiercely feel belongs to all of us. The script might have worked if it were more complex, an epic of all the survivors and their families, or, alternately, if it were more stripped-down. (And it wouldn't necessarily be offensive if it were broken up more imaginatively as the two men's minds inevitably wander.)
In fact, the best thing in the movie is a stretch in which burning matter starts raining down on the trapped officers; it heats the space up so much that the service revolver of one of their fallen comrades starts spontaneously firing. Jimeno screams because he's getting burned, but McLoughlin is so purely terrified he's screaming, too. This is the one moment when you feel that Stone has recreated what it must actually have been like to be down there — at the center of the debacle and yet almost entirely in the dark. (When Jimeno is pulled out on a stretcher we find out he didn't even realize that the towers had collapsed.) Cage, that most physical of talkity actors, and Peña play most of the movie with only their faces visible, covered with dust and lost in shadows. In those few horrifying minutes, Stone reduces the movie to sheer experience, and it's probably the most powerful filmmaking of his career, because you don't have to discount it for his usual bombast and coarse expressionism.