Large scale urban redevelopment projects have become the most visible revitalization strategies pursued by cities in search of economic growth and competitiveness. In the light of a profound socio-economic change and tight public budgets they have become an important policy tool in the new Berlin. Town planners actively engage in cooperation with private partners who take charge of managing the development of large urban areas. This process is illustrated by the Berlin-Adlershof development project. The aim is to create a "new city" of science and the economy. The case study examines how the urban revitalization project is embedded in the institutional framework and socio-political dynamics of the city. Large projects are a high-risk endeavour because they constitute a challenge to democratic decision-making procedures and to the public budget. These operations present considerable potential for the removal of political control and require funding on a massive scale. If their realization runs into trouble, the project plans are difficult to modify. Here we discuss why large projects quickly reach the point of no return. Self-binding patterns, financial dependencies, and complex webs of relationships keep "the machine" running. The case study demonstrates that when urban development policy attempts to exploit the market it can easily drift into troubled waters.