Werner Herzog's rousing true story, Rescue Dawn, about a pilot (Christian Bale) who engineered a daring escape from a Laos POW camp in the mid-'60s could be misconstrued as yet another mainstream actioner. Not surprisingly, the obsessive director has deeper pursuits, and he unspools themes of valor and loyalty with a spare beauty. EXTRAS include Herzog's intimate commentary and a doc in which Bale and costar Steve Zahn recount eating maggots, running barefoot in the jungle, and swimming in snake-infested waters. The shoot ''was a blast,'' Zahn assures us. B+

