The gist of "it," as Richard only found out much later (he was a big believer in delegating responsibilities to people who actually cared about them), was that the T’Rainian biosphere supported two distinct types of DNA, one made exclusively out of original T’Rain elements, the other commingled with trace amounts of stuff from the swallowed planetesimal and therefore imbued with "magic," where "magic" was now a social construct invented by T’Rain’s sentient races to explain the different physics that governed the alien atoms. Some species were made entirely of the mundane DNA, some were hybridized with a bit of the alien stuff, and a very few were made of 100 percent alien material and consequently had angelic/demonic/godlike qualities, though these had trouble reproducing since it was difficult to round up a sufficient biomass of the right kind of stuff.