Carnage season is in full swing in the film world, with Death Sentence, Exiled, 3:10 to Yuma, Shoot 'Em Up, The Brave One and In the Valley of Elah oozing blood from seemingly every screen in town. But nothing can match the epic brutality of exploitation king Ken Burns, whose latest PBS opus, The War, devotes 15 hours to revisiting World War II. Focusing on four American towns, including Sacramento, Burns' view encompasses the war at home as well as in Europe and the Pacific. The series debuts the week of Sept. 23 on public TV, but the DOC Film Institute at S.F. State presents the whole enchilada in one weekend marathon at the Presidio -- with the big enchilada himself on hand to introduce several episodes and field questions. Who needs fake bullets and fake deaths when the real thing is so close?