We argue that the possibility to generate content into vast areas is a relevant challenge in the area of location based pervasive games. In this paper, we present a game prototype that enables children travelling in the back seat of a car to enjoy a narrated experience where game play combines with the experience of traveling through the road network. The prototype is designed to provide, what we refer to as a believable environment. We sug­gest four design characteristics to provide a persuasive inclusion of a journey into a pervasive game. First, the story should refer to geographical objects with their everyday meaning. Second, the game needs to scale over vast areas. Third, the application should provide sequential storytelling to make it fit with the journey ex­perience, and finally it should provide interaction support where players can engage in gameplay and interact with the computer in various ways at the same time as they are looking out of the car window. We describe how these requirements have been imple­mented in the prototype and present an initial performance test.