Although this is the fourth of the novels in the emortality series, it comes first in time. It's set about 2040 and deals with a mystery to do with early research into the technologies, against a background of the beginning of what the later stories call 'the Crash'.
The story here is more interesting for what it informs of the later stories than on its own. Specifically, some of the twists and turns get pretty implausible by the end. Of course the mystery is really there to highlight issues about the human reluctance to deal with things (such as population growth and climate change).