How can people and organisations best respond to emergency events that are significantly beyond the boundaries of what they had generally anticipated, expected, prepared for – or even imagined? What forms of organisations are likely to be best able to cope with such events – and what procedures and practices will aid in their ability to do so? Obviously, extreme events – events that are in scope or scale or type beyond the range of our ordinary experience and expectations – by definition will occur only relatively rarely (and very rarely to any given emergency organisation). Nonetheless, when they do occur they tend to be of defining importance to the people and institutions that are thrust into them and that must find their way through them. September 11, 2001 in Manhattan and at the Pentagon in Arlington, Virginia; the Indian Ocean Tsunami in 2004; Hurricane Katrina on the Gulf Coast of the United States (US) in 2005; major earthquakes like the ones in Pakistan in 2005, Wenchuan in 2008, Haiti in 2010, Chile in 2010, and Christchurch in 2010 – these and other catastrophic events catapult people and response agencies into a new, unfamiliar, and largely unexplored dimension.