Can you trust an AI model to do what you intended? This is a central question both for those deploying AI systems and for those seeking to evaluate their capabilities. In deployment, a model that pursues a goal through unintended or unauthorised means may cause harm, particularly in high-stakes use cases. In an AI capability evaluation, the same behaviour may undermine the validity of the result: the model may appear to demonstrate a capability by completing a difficult task, when it has instead...