Let’s talk about sarin. According to the U.S. Centers for Disease Control and Prevention’s Web site, it’s one of the most “toxic and rapidly acting of the known chemical warfare agents.” Kinda like some pesticides, the entry continues, except that “nerve agents are much more potent than organophosphate pesticides.” You might call sarin the granddaddy of nerve warfare: Developed by accident in Nazi Germany, it’s since been used by the likes of Saddam Hussein and those Japanese cult people back in the mid-’90s who were pretty excited about the idea of ending life on Earth. The CDC says that the agent works by “preventing the proper operation of the chemical that acts as the body’s ‘off switch’ for glands and muscles.” Without that function, the report continues, “the glands and muscles are constantly being stimulated. They may tire and no longer be able to sustain breathing….” Sounds like fun. And there are others. Plain old chlorine gas was used in World War I, and during the Cold War, both the United States and the Soviet Union raced to mount stockpiles of such battle-ready agents as VX, which kills in doses as small as the head of a pin. So Jonathan Tucker had plenty to write about when he took on the task of chronicling the recent history of these things in War of Nerves: Chemical Warfare from World War I to al-Qaeda. Tucker appears at 6 p.m. at Politics and Prose, 5015 Connecticut Ave. NW. Free. (202) 364-1919. (Mike Kanin)