The affinity trap - Martin Sketchley

Vourniass Lycern -- a conosq of the three-sex Seriattic race -- holds the key to peace between Earth and Seriatt, and thus the continuation of the lucrative illegal arms trade conducted by General William Myson.
When Lycern decamps to the Affinity Group complex on Veshc, Myson orders experienced Military Intelligence Officer Alexander Delgado to fetch her. While once respected, the changes that followed Myson's rise to power saw Delgado's position reduced in all but name, his independent character and methodologies unwelcome. But Delgado, sees the mission not as a chance to reinstate his name to the position of respect it once held, but an opportunity to engender a much greater level of change.
When he comes into contact with Lycern, however, Delgado faces his greatest ever challenge, the consequences of which have the ability to change his life -- and potentially the future of Earth -- forever.
In the first of the Structure novels, Martin Sketchley has created a vivid widescreen setting in which the boundaries between good and evil, male and female, human and non-human are often indistinguishable despite the wishes and perceptions of the startling characters he has created. Sexuality, gender roles, and the fundamental drives of every human being are explored within a gripping dynamic storyline that highlights the contrast between what humans perceive themselves to be, and what they really are.