A Kiss of Shadows by Laurell K. Hamilton
"All it would take was my true name being mentioned after dark, and it would float back to my aunt. She was the Queen of Air and Darkness, and that meant that anything said in the dark was hers to hear, eventually. The fact that spotting the missing Elven American Princess had become more popular than spotting Elvis helped. Her magic was always chasing blind leads. Princess Meredith skiing in Utah. Princess Meredith dancing in Paris. Princess Meredith gambling in Vegas. After three years I was still a front-page story for the tabloids, though the latest headlines had been speculating that I was dead as the King of Rock and Roll . . ."Three years ago, Princess Meredith fled the court of her cruel Aunt Andais, the Queen of Air and Darkness, leaving that garden of decadent delights and backstabbing intrigues for the comparative calm of Los Angeles. Using her magic to pass for human, Meredith began a new life as a private investigator specializing in supernatural crime. But now Doyle, the