When they met and fell in love, during the declining years of King George III, Miriam promised John that their love would endure forever. She lied, as she had lied to other lovers over more than two millennia, not in a spirit of deception but of hope. Today, John is not even 200 years old, and already his powers are beginning to fail, while Miriam remains as young, beautiful and full of vitality as ever.

The problem is that Mariam is a genetic vampire, while poor John is a mere mortal -- promoted temporarily to vampire status through a primitive blood transfusion long ago. In terms of durability, he is not in a class with Eumenes, who had been a fighter in the revolt of Spartacus, or Lollia, a Byzantine Greek who joined Miriam in Ravenna during the barbarian invasions of the Roman Empire, and who lasted nearly 1,000 years.

John's decline, in their elegant town house in Sutton Place, is a pitiful thing to watch: the vampire blood in his system (which has two extra leukocytes not granted to ordinary mortals) can no longer be satiated with a weekly infusion from a human victim. John must go out hunting more and more often, and finally no amount of human blood is enough; the vampire blood begins to devour the cells of its host, reducing him finally to a poor, shriveled thing that cannot die because its blood is immortal.

Miriam suffers along with her lover until he tries to make her a victim. Then she defends herself but, true to her old promise, she still loves him; she will love him forever, and she will keep his undying remains in a strong box in her attic, with the boxes that contain the undead relics of all his predecessors. But one must be practical, and meanwhile she is busy recruiting her next immortal lover.

Whitley Strieber's first novel, "The Wolfen," was a strikingly original approach to the werewolf theme. His second, "The Hunger," is an equally impressive treatment of vampires -- a more complicated assignment. Werewolfs are relatively simple creatures compared to vampires; even when they are as intelligent as Strieber's, they represent nature, red in tooth and claw, at its most elemental. Despite their unfortunate dietary preferences, they are well-adapted to their own curious social structures, firm in their adherence to a werewolf code of ethics, and touchingly family-oriented -- on the whole, more admirable than the human derelicts who are their fundamental food supply.

Vampires are more of a problem, in the popular imagination and in Strieber's treatment, which is innovative but faithful to the essentials of tradition. There is a foulness about them, a diabolical overtone not found in the werewolf, which can almost be mistaken for a large, intelligent dog. Garlic and crucifixes do not bother Strieker's vampires, though a stake through the heart will kill them, as will fire.

In the normal course of events, vampires seem to live forever, but they do not breed as prolifically as werewolves, and Miriam suspects that she may be the last surviving member of her species. She must interact with humans not merely in the simple relationship of hunter and prey but in the much more complicated one of proselytizer. The proselytization involves intimate personal contact, in which the kinky sexual overtones always implicit in vampirism become erotically explicit. In an age when practically nothing sexual is forbidden by society, Strieber has found one activity that still is. And he exploits it to the fullest.

As John's successor, Miriam decides to proselytize Sarah Roberts, a brilliant young medical researcher whose work on the aging process has put her almost in reach of the vampires' secret. With her scientific skills, Miriam believes, Sarah may be able to break through into true immortality, unlike previous lovers who have merely postponed the inevitable. As part of her plan to recruit Sarah, Miriam submits herself for medical research and allows her prospective victim and a few associates gradually to realize what she is.

The byplay of this process pinpoints neatly the vampire's anomalous position in human society. Miriam's mother, whose portrait she still has, was worshiped before the dawn of history as the demi-goddess Lamia, who had the nasty habit (as Robert Graves reports in "The Greek Myths") of making love to young men and drinking their blood while they slept. At Riverside Hospital in New York, when the blood tests and X-rays begin to be understood, Miriam is described as "history's most important experimental animal."

Goddess or animal -- she is neither and both; something outside of human frames of reference but interacting intensely with humans; both pitiful and terrifying; larger than life but strangely vulnerable in her isolation.

Strieber has placed her at the center of a vivid, skillfully written novel, striking in the feral spirit that imbues its scenes of hunting and killing, fascinating in its psychological overtones, and a bit repellent in its subject matter, but certain to attract a large readership precisely because of what makes it repellent.