The one yearly hosted Cyber Defence Exercise (CDX) challenges teams of students from American and Canadian Military Post Graduate Academies with the challenge of designing, building, and successfully defending a real-world computer network against advanced and coordinated intrusions by a team of dedicated, persistent and very advanced adversaries; Otherwise known as the Red Cell. This Red Cell consists of experts from private industry, US Department of Defense (DoD) and Canadian Department of National Defence (DND/CF) personnel over a intense non stop three-day period - 72 hours of unrelenting attack. CDX strives to provide students a sense of the dangers that will exist in a realistic and hostile network environment, sound and effective network defence strategies that can mitigate those dangers, and realistic strategies that can be applied even with manpower and financial resource limitations. This presentation will depict the challenges of leading and coordinating the Red Cell towards very effective attacks and exploitation of students' information systems with devastating impact. The end goal is to present the next generation of information system defenders with a simulated real world attack environment which holds nothing back and takes no prisoners.