A strange one, and very obviously from the very early years of Trek fiction (this appears to have been only the second Trek novel that wasn't an episode adaptation). It has a halfway decent Trek plot at its core, but suffers greatly from being written during the 70's period of "every future society must be far more sexually evolved than ours, and we're going to tell you all about it, even though we're still fairly sexist in our thinking" science fiction writing. While I have nothing against an open approach to sexuality -- in fact, I highly approve of it -- this felt far too much like a clumsy melding of Trek and bad fan-written soft porn.