Borrowing a pair of fox fairies from Chinese folklore, Tompert tells a story about a series of magical changes, in each case including an appropriate tangram. (A tangram is a square divided into seven geometric figures that can be rearranged to represent any number of things.) At first, the foxes change themselves into a predator and a pursued animal, with subsequent changes preserving that relationship; ultimately, the predator drops his aggressive role and joins his friend as a goose, just in time to help him after he is wounded by hunters. A deftly fashioned framing story helps introduce the tangram concept, which is also explained in a note. Parker's gently suggestive illustrations echo both the cleverly arranged tangrams and the animals they represent. A nicely worked-out tribute to a bit of Chinese cultural heritage.