The European Union now finds itself in a liminal space-a 'constitutional borderlands'-between its traditional role as a prodigious producer of regulatory norms and a nascent, yet incomplete, role that seeks to develop fiscal capacities to achieve its goals. The NextGenerationEU (NGEU) programme adopted in the wake of Covid is at the heart of this shift. It defined a new model of non-transparent, executive-technocratic governance that was then repurposed to address the many challenges of the Russian war on Ukraine as well as other pressing needs.This book provides the first comprehensive analysis of the design, implementation, and evolution of the NGEU model from its inception to today. It subjects the model's hidden mechanics to a critical examination, exposing the pivotal role of EU institutional legal advisers, operating behind closed doors, in facilitating revolutionary reinterpretations of the Treaties that effectively bypassed the democratic process to transform the nature of European governance. It shows that the advent of the NGEU model has had profound distributive and democratic consequences, shifting power toward executive and subordinate technocratic actors while sidelining parliamentary oversight and the involvement of other stakeholders. At the same time, the NGEU model created misaligned incentives, often prioritizing national spending envelopes over the production of genuine European public goods. These 'emergency' measures are fast becoming the new normal. The core innovations of the NGEU model-national planning, performance-based financing, and enhanced Commission discretion-form core elements of the Commission's proposals for the next Multiannual Financial Framework (2028-2034). This book warns that without a return to open democratic politics and constitutional deliberation, the EU's navigation of the borderlands in which it currently finds itself risks eroding legitimacy and creating a fragile system unable to meet future challenges.