The Timeservers

Officer Calvin Troy, new boy at Earth Embassy, faces a first mission against alien minds that kill in alien ways. But facing death is his duty. Even if his co-officer is a totally dangerous woman. Who might no longer be totally human. In a war across a time zone when humanoids and clones have infiltrated the race, Calvin Troy will have to battle a terrifying possibility: He is not the only Calvin Troy. And if that is so, then just how human are the rest of his fellow timeservers?