Urban Shaman by C. E. Murphy
"Joanne Walker has three days to learn to use her shamanic powers and save the world from the unleashed Wild Hunt.
No worries. No pressure. Never mind the lack of sleep, the perplexing new talent for healing herself from fatal wounds, or the cryptic, talking coyote who appears in her dreams.
And if all that's not bad enough, in the three years Joanne's been a cop, she's never seen a dead body—but she's just come across her second in three days.
It's been a bitch of a week.
And it isn't over yet."
Mass market, a decent copy