Abstract Whether in terrestrial or aquatic habitats, the material qualities of water make it an exquisite and drastic connector. Water is in relation and creates relation, rendering the planetary water cycle inescapable when being on earth. Accordingly, human-water relations are both, a matter of more-than-human kinship relations and of transcultural connections. This paper analyses Nnedi Okorafor’s Lagoon (2014), a novel presenting an imagination that puts absolute attention on more-than-human entanglements and emphasises water as a crucial agent of such entanglements. As an angry swordfish stabs a hole into an oil hose, aliens land in the waters of Lagos, and human characters transform into mermaids, Lagoon deals with concepts such as petroculture and planetary health and suggests an organic chaos of relationality as a relief to an artificial order of separation. Lagos, notorious in fiction and reality alike, transcends the role of mere setting in Lagoon , and instead appears as a huge being, formed by the intra-actions of its inhabitants. While emphasising the local, the diversity of its perspectives and the strong focus on relationality give Lagoon a planetary sense, but with a decidedly African twist. As part of Okorafor’s Africanfuturist vision, it is Lagos, Nigeria where the future emerges.