Courtsey of Time (oddly enough):
U.S. intelligence got its first inkling of the plot from the contents of a laptop computer belonging to a Bahraini jihadist captured in Saudi Arabia early in 2003. It contained plans for a gas-dispersal system dubbed “the mubtakkar” (Arabic for inventive). Fearing that al-Qaeda’s engineers had achieved the holy grail of terror R&D — a device to effectively distribute hydrogen-cyanide gas, which is deadly when inhaled — the CIA immediately set about building a prototype based on the captured design, which comprised two separate chambers for sodium cyanide and a stable source of hydrogen, such as hydrochloric acid. A seal between the two could be broken by a remote trigger, producing the gas for dispersal. The prototype confirmed their worst fears: “In the world of terrorist weaponry,” writes Suskind, “this was the equivalent of splitting the atom. Obtain a few widely available chemicals, and you could construct it with a trip to Home Depot – and then kill everyone in the store.”
