"The United States, 1847. A disparate group of young American soldiers are bound to join General Winfield Scott's campaign against Santa Anna at Veracruz during the Mexican-American War. They never arrive. Or rather . . . they arrive somewhere else. The untried, idealistic soldiers are mostly replacements, really; a handful of infantry, artillery, dragoons, and a few mounted riflemen with no unified command. And they've been shipwrecked on a terrible,...