"U.S. intelligence analysts have been closely examining satellite images of the west bank of the Tigris River in Baghdad for signs of a laboratory rumored to exist there. Called Tahhaddy, or "Challenge," the lab is purported to have 85 employees and a top-secret mission: making biological weapons for Iraq's military. Details about the lab have trickled out of Iraq in recent months in accounts from defectors and Iraqi exiles opposed to President Saddam Hussein. They tell of underground test chambers, heavy security and a viral strain code-named "Blue Nile," which sounds suspiciously like the Ebola virus."