The Superman movement argues vociferously for the abolition of laws, mostly passed when human genetic modification was first permitted, which forbid the modification of a genome to create a being who does not inhabit human “G-space”. The movement’s members want to be able to create people who could not, even in principle, have come about as a combination of known, natural human genetic sequences. They believe computer modelling is now so good that the consequences of DNA changes outside G-space can be predicted, and that the risk of “inhuman” monsters can thus be obviated. No jurisdiction yet permits this. But, given the simplicity, these days, of editing DNA, it is hard to believe there is not, somewhere in the world, just such a being preparing to celebrate its own second C-day.