Rusalka — C.J. Cherryh

A PERILOUS LOVE
In the folk-tales of pre-Christian Russia, the most dangerous ghost of all was the Rusalka, a murdered girl still seeking to exist by drawing the energy of life from all nearby living things.

Once Pyetr Kochevikov had mocked belief in magic, as he rioted through life with the young blades he thought his friends. But now, outcast from his native city, his only friend was Sasha Misurov, a young man fearful of his own beginning magical powers. Pyetr and Sasha had found safety in the forest cottage of the old wizard, Uulamets. Or it had seemed to offer safety, if not warmth.

Now Pyetr was less sure it was safe. The dvorovoi, or Yard Thing, accepted young Sasha, but the vodyanoi, or River-Thing, had tried to kill Pyetr, and he had met the ghost of Uulamets' murdered daughter, the Rusalka the wizard was trying to call back to life.

The worst of it was that Pyetr felt himself falling in love with her, as she seemed to be with him! But no love could quench her need for the life-sustaining energy within him. And no man could long suffer that drain and live.