In 2002, the Magna Science Centre in South Yorkshire witnessed a surprising event: a two foot tall robot, Gaak, escaped from a gladiatorial experiment with learning robots. The experiment, part of the “Living Robots” project, simulated a predator and pray scenario where some robots searched for food (prey) and others hunted for them (predators). Gaak, a predator, was left unattended for fifteen minutes and, in that time, managed to find and navigate along a barrier, find a gap, move through it and continue across a car park to the M1 motorway. Gaak was found rather quickly when a motorist almost collided with it. This story of robot liberation helps us to understand a simple fact about learning machines: they are unpredictable. This should guide us when thinking through the role of artificial intelligence and robotics in contemporary warfare, especially if we think there are morally right and wrong ways of using lethal force.