In this paper we describe a high-end pervasive larp Momentum that sought to create a seamless merger of life and game for the game duration of five weeks. During the five weeks the players could be able to play an immersive game set in our ordinary reality augmented with game content, both through narrative content and through game artifacts. The central challenges of the long duration was merging the game and life in a functional manner, game mastering the game for extended periods, and pacing and structuring the game in a working way. This paper looks into the lessons of Momentum; problems, solutions and other evaluation results.