There is the future that we can predict, and then there is the unexpected. In an obvious way, the unexpected is the failure of prediction, and in a less obvious way, it comes into view as a result of the success of prediction. Prominent unexpected events, such as 9/11, the tsunami in the Indian Ocean in 2004, the financial meltdown of 2008, are moments that highlight our everyday reliance upon and expertise in prediction. Expert prediction is what we hold to account in the event of the unexpected. In moments of catastrophe, in cases of child abuse and murder, for an unforeseen storm, there is always someone who should have seen the future coming. Even creative writing tutors were expected to have foreseen the unexpected in the Virginia Tech massacre in April 2007. Perhaps it is part of the same logical co-dependence that, in an age driven by financial forecasting, market research predictions, electoral polls, the actuarial sciences, climate change projections and widespread gambling – in an age of increasingly interested, detailed and accurate prediction, the notion of the unpredictable has emerged as a way of characterising the new epoch. The notion of unpredictability comes with a certain scientific credibility in the contemporary age, which derives from difficulties in the modelling or simulation of complex systems in biology: systems so fundamentally complex that their behaviour cannot be encapsulated in a formal model, and therefore cannot be predicted.