“Who controls the River Thames?” remains contested. While often framed as human-controlled, the river acts as an active agent shaping social, political, and environmental relations. This project reimagines the London Super Sewer as a liminal space of negotiation, where landscape mediates between human and natural forces. Across scales, stakeholders appear as players in a model, yet in reality the Thames operates as an “uncontrollable controller,” gradually reshaping the site and revealing long-term outcomes.