Did the Holocaust really happen the way they say it did—6 million dead, gas chambers, and all? Or was it a modest military “relocation” effort that, well, ran amok? A growing contingent of “scholars” is bent upon proving the latter, even going so far as to claim the gas chambers were used only to fumigate clothing. History should be open to debate, but the Holocaust revisionists represent a worrisome phenomenon, not least because a fifth of all Americans say they are open to the possibility that the bad thing never happened. How timely, then, is Deborah Lipstadt’s Denying the Holocaust, a thoroughgoing refutation of the Holocaust-refuters. Lipstadt will dissect the denial movement Sunday at 2 p.m. at Politics & Prose, 5015 Connecticut Ave. NW. FREE. (202) 364-1919; and again Sunday at 5:30 p.m. at the United States Holocaust Memorial Museum, 100 Raoul Wallenberg Place NW. FREE. For reservations call (202) 488-0458. (Bill Gifford)