The mode of transport used by the “railhopper” came out of a concept combining mutations and prostheses. First and foremost, the system is based on an improvement in the weight-power ratio for a human being obtained by controlled mutations, just like birds: these creatures have been given hollow bones as resistant as solid bones and much lighter. They also use an exoskeleton with powerful springs. A man can easily travel at approximately 20 mph on a bicycle, but he can’t run at that speed, or not for as long, without tiring himself more. The cyclist is actually putting all his muscular energy into his movement. By contrast, a runner running a race is using a large part of his strength for a braking action against the weight of his body when he touches the ground. The artificial limbs are intended to re-use all the strength produced by each jump. The energy absorbed and stored in the springs after each jump is restored to create a new bound. The movements are improved by wings, which make it possible to gain support from the air and to increase the distances leapt. Some of these wings, inflated with helium, can also have a protective function, acting as an airbag. Thanks to these evolutionary developments, movement has become a kind of dance, and this offers humanity a new mode of expression. Everyone dresses up in colours, veils and feathers. People express themselves and blossom into movement which is simultaneously a way of pleasing, a way of expressing desire, of displaying one’s artistic behaviour or of entering into contact with other people.