In the far future a mutation develops and humankind is split into Simes and Gens. Simes "change over" at adolescence into vampire-like creatures that must suction off energy from Gens every month. Ordinarily, this causes the death of the Gen. But then "Channels" are discovered who could safely take energy from Gens and give that energy to Simes. Digen Farris is a channel with an injury that keeps him from functioning as one, but does allow him to take training as a surgeon, a lost art among Simes. And then he meets this Gen... Both Lichtenberg and Lorrah who write books in this series are both good storytellers and create characters to care about. And since each book was written to be read independently, this one can stand alone.
