Not of This World — Tracy St. John

The drug Delir is sweeping the Kalquorian Empire, leaving madness and death in its wake. Investigator Dramok Gelan has already lost his enforcer partner in a deadly shootout because of the case. With no clues or suspects, he despairs of putting an end to the epidemic. Then a familiar face enters the picture: new partner and former lover Nobek Wynhod.

Wynhod never forgot the Dramok he loved seven years ago, and his assignment as Gelan's enforcer is no accident. However, Delir doesn't kill just its users; those who get in the way of its contagion die too. With the addition of a savvy criminal psychologist and a lucky break, Gelan gets too close to the truth.

Imdiko Krijero is a brilliant psychologist with insight into the criminal mind. Gelan and Wynhod pierce the man's awkward facade to discover their perfect third ... but Krijero's broken heart from a past affair keeps them at arm's length. Can the pair convince this reluctant partner to give love a second chance? And can they save Krijero when Delir's evil mastermind discovers the psych knows his identity?

This book is the prequel to Clans of Kalquor 5: Alien Slave.