We survey the space of three-dimensional mobile visualizations, that is, 3D abstract or spatial data on mobile 2D displays, or mobile head-mount augmented- and virtual-reality displays. As a playful “case study” we use a scenario from the film “Aliens,” in which a mobile, small-screen visualization device is used to track the movements of enemy aliens around a group of space marines. In this scenario, the marines are overrun by aliens in the ceiling, as their device fails to show them the height dimension of the space around them. We use this example to illustrate how different mobile and 3D interaction techniques could have prevented the misunderstanding in the movie, using both hypothetical descriptions of the improved movie action and a scientific discussion of these scenarios and their implications