The Dark Winter exercise, held at Andrews AFB, Washington, DC, June 22-23, 2001, portrayed a fictional scenario depicting a covert smallpox attack on US citizens. The scenario is set in 3 successive National Security Council (NSC) meetings (Segments 1, 2 and 3) that take place over a period of 14 days. Former senior government officials played the roles of NSC members responding to the evolving epidemic; representatives from the media were among the observers of these mock NSC meetings and played journalists during the scenario's press conferences. https://centerforhealthsecurity.org/our-work/tabletop-exercises/dark-winter-a-training-tabletop-exercise