The concept of assemblages has gained an important degree of momentum in urban studies claiming to offer a new ontology for understanding cities as emergent and fluid concatenations of multiple elements. Such a conception, however, has also been criticised in relation to its supposed failure to deal effectively with the issue of power and inequality in urban dynamics. This paper contributes to this on-going discussion by exploring in detail the way in which power was embedded in one particular case: a bus stop shelter located in front of the Biblioteca Nacional in Santiago, Chile. In so doing, it analyses the controversy arising when two large and complex urban assemblages share component/s that each of them claims as exclusive. This situation made necessary practices of co-ordination in which a hierarchy was established between the competing assemblages, involving important transformations in some of its components.