Animated film explains the theory that Earth's land areas are fluid and that, in the process of a slow, rolling, boiling motion, one part of the Earth might well be engulfed and then rise again some distance away, much the same as froth on a kettle of soup. From this theory comes the idea that continents were formed from one super-continent that broke up, whose pieces sank, and then rose once more, but far apart. Introducing the film is Professor J. Tuzo Wilson, geophysicist, University of Toronto.