achieve near light-speed in the Disc’s magical field. This means that if you can see a puzuma, it isn’t there. Most male puzumas die young of acute ankle failure caused by running very fast after females which aren’t there and, of course, achieving suicidal mass in accordance with relativistic theory. The rest of them die of Heisenberg’s Uncertainty Principle, since it is impossible for them to know who they are and where they are at the same time, and the see-sawing loss of concentration this engenders means that the puzuma only achieves a sense of identity when it is at rest – usually about fifty feet into the rubble of what remains of the mountain it just ran into at near light-speed. (P)