Conspiratorial thought is one of the hallmarks of late modernity. This article focuses on the wealth of conspiracy theories that crystallized around chemtrails and the Californian drought to examine the genre more generally. It suggests that the particular constellation of certainty and doubt present in conspiracy arguments is a product of the fundamentally mimetic nature of conspiratorial thought, which espouses the contours of the infrastructural environment in which it emerges. In our case, this infrastructural environment is that of bureaucracy on the one hand and the architecture of the internet on the other. Each of these infrastructures helps to shape conspiratorial thought in a distinct manner, and the confluence of the two imparts to the genre its particular flavour.