Previews of movies “embody the great promise of modern consumerist entertainment: that there will always be more. They are like the still-wrapped packages under a Christmas tree: the one you are about to tear into might turn out to be a pair of wool socks or a cheap knockoff of the toy you really wanted, but there is still all this other stuff yet to be opened up. Whatever disappointments the movies themselves might bring are safely in the future, as you feel the rush of all their expensive promise — the fights, the explosions, the computer-generated imagery, the macho repartee — in compact, thrill-packed doses. Big, commercial movies may rarely be surprising these days, but the possibility that they might be is always there.”