This was quite a debut novel back in 1995. Reading it now it reminds me of some of Robert Holdstock's books, not just Mythago Wood transposed into the sentient lywyn forest with its ghostly figures drawn from memories, but stories such as Where Time Winds Blow and Earthwind in which sentience can exist outside corporeal bodies.
The idea of using two fairly separate stories told in more or less alternating sections and finally bringing them together to answer the question: why did all these terrible things happen, comes close to functioning. It doesn't quite because having two stories introduces an awful lot of characters, many of which have to disappear or die to make the final single story workable. The Pickled Brains meet their end in a computer induced maelstrom of destructive data; Jenae's twin sister is finally polished off by a killer virus; Tien fades from sight in Jakarta; Keila the one-eyed, along with several scientists board their spaceship and leave Underkohling for Earth; the too-smart-by-half dolphins swim away into obscurity. There are others but it is only when they have gone that Tsering and Daire can meet their inevitable tragedy.
One character who is brought into prominence as the story approaches its finale is the affable British scientist Colin. I don't know if the author's idea was to make him a rival for Tsering's affection. If so, for me it didn't work. Colin is and remains a well-meaning, nice man who finally listens to Jenae and believes what she has found out about the original directors of the evil Ingenix corporation. He begins as a tool to keep the story moving and pretty much stays that way until near the conclusion he wanders off to do more research in the lywyn, allowing Tsering and Daire to act out their bitter parting.
There is some shortage of explanations. Most obviously what is Underkohling and why is it called Underkohling? I can only guess it's an alien construction to hold worm-holes in place that has somehow drifted on to the edge of our Solar System. If the directors of Ingenix wanted to kill off the children they had been using for experiments why choose such a brutal and heartless way of doing it; why not use their virii to simply kill them? And for so long in the early part of the story we have the impression that “pure humans” are few in number and struggling to survive in their protective rezs, then Jenae travels to England, and London seems to be a thriving metropolis filled with people. There is even an active spaceport at Bergen in Norway.
Anyway, if you let your imagination loose, it all makes for an excellent fast-paced dystopian tale of genetic warfare, greed, power struggle and a fight for survival. Now, if you'll pardon me, I'll just slip into altermode and have a quick bath.