Oh, my, more vampire books.
These novels by Steven Spruill are not new. I actually picked up the second one first and finally ordered the first one from a used book store as it is out of print. I have to admit that I like vampire books, although these are not top-notch. But the premise on how a vampire is born is different in these books than in others. In Spruill's world, vampires are called hemophages and the condition is genetic. Some few humans become ill with leukemia at puberty. If they are able to obtain blood, they transform into vampires. Otherwise, they die.
With this premise, they can't infect normal people or make people into vampires, so a great deal of the threat/temptation of the vampire meme is sort of lost. Much of the underlying sensual attractions of other vampire series such as the Anne Rice books or the Twilight saga is the love/hate relationship that the reader, as a "normal" has with the idea of vampirism. You could live forever, have great powers, and be nearly immortal - but you have to kill people and drink blood to do it. That moral dilemna is absent here.
Merrick Chapman, a nine hundred year old hemophage, is a police detective (he gets the first information when another phage might be responsible for killings) and is able to catch them and cover up the existance of the breed from normal people, thus keeping himself safe. Merrick has trained himself to exist by stealing blood through transfusions rather than by killing, but apparently his restraint is rare (and scorned by others of his kind). Since the only way to kill a phage is to deprive it of blood, he has a secret dungeon where the captured phages slowly starve to death. It's quite a grim premise.
But Merrick's weakness is that he loves humans. He wants to be a shepherd rather than a wolf. He falls in love, marries, then eventually must fake his own death (since he doesn't age) and move on, but he stays faithful to each wife until she dies, even though she, thinking him dead, doesn't know it. He also has had children, but only one, Zane, has become a hemophage.
In Rulers of Darkness, Zane and Merrick clash as Zane wants to rid himself of Merrick so he can kill with impunity, and Merrick wants to imprison Zane to keep him from murder. But Zane has a daughter, and she is twelve and ill with leukemia. Merrick knows what she is, and feels he has to let her die, but after Zane gives her blood, Merrick's goal is to teach her to live without killing.
Daughter of Darkness is Jennifer's story as she becomes a young woman, grows into her life as a hemophage, and falls in love. But when some gristly murders begin again, she has to ask herself if her lover, Hugh, is a hemophage - and if she really wants the answer to be yes.
Both are decent books, worth an initial read but not a second one.