We advocate the theme of complicity, ahead of co-operation, as a means of understanding complex, interactive digital systems. Our case study of a market precinct known as the Barras, about one mile from the centre of the city of Glasgow, foregrounds the notion of complicity. Market places are characterized not only by co-operation in rule-governed environments, but complicity between actors as a means of breaking rules, working at the boundaries of formal frameworks, avoiding other actors, such as law enforcers, and even working with them in tacitly agreed evasion strategies. We present the human voice (as exercised in the case of market stall holders drawing attention to their wares) as a major medium of complicity. In our application of these ideas we deploy Lego Mindstorms TM RCX robot processing to explore interactions between a mobile sensing robot and simple environmental controls: movements of sliding screens in response to an autonomous mobile sensor. As well as their benign characteristics as co-operating agents, we argue for a consideration of robots as quintessential tricksters, plotting and scheming strategies of survival, evasion and opportunism. Traits that can be employed in the development of useful augmented environments.