In this too-human tale, social media is taken to another level.  Through a new testing process, people can be linked to others with whom they are most compatible.  This goes beyond mere dating; this is socialization on a grand scale.  Once identified with one of the twenty-two described Affinities, one has the opportunity to have a whole new family – of all others in the Affinity - worldwide.  But loyalty is tested as the Affinity is expected to be all one needs.  A person with an outside affiliation like a friend, spouse and even children are said to be ‘tethered’ -  a rather negative connotation.  And all those who fail to test into any of the twenty-two groups are left with a feeling of being excluded.

Our main protagonist, Adam, is down on his luck, coming from a dysfunctional family, and adrift without a purpose when he decides to be tested.  To his great surprise, he not only tests into an Affinity but into Tau, one of the most populous and influential.  His whole life changes when he meets people who truly love him for who he is; people with whom he connects so easily that nothing seems impossible.  And there are visionaries within Tau who see a future where the Affinity would be threatened from without and projects are in motion to ensure their future.

Those without an Affinity begin campaigning against Affinities; looking for an alternative to social organization that doesn’t exclude anyone.  But the greatest threat ends up being from another Infinity – Het.  Where Taus are social, individualistic yet organized, the Hets are jack-booted functionaries all marching to the same tune:  world domination.

Eventually, Adam is forced to choose between his Affinity and his ‘tether,’ but, as it turns out, it was never really his choice.

This story has a grand idea to explore but I didn’t think the author took it far enough.  I found the plot to be too passive.  For most of the book, there was no real conflict and even when it was introduced, it, too, was passive.  I would have been happier at the end if there had been a more clear resolution.  I do recommend it, though, if for no other reason than an opportunity to discuss what comes after Facebook and Twitter.  ~~  Catherine Book