Showing Medicine Road by Charles de Lint

Marking the return of the mischievous, red-headed Dillard twins, this bewitching fantasy entangles the lovely sisters in a 100-year wager in the Native American spirit world. Laurel and Bess are touring bluegrass musicians who encounter two mysterious strangers with a powerful secret in Tucson, Arizona. In addition to their animal natures, Jim Changing Dog and Alice Corn Hair have been given human forms by the powerful Coyote Woman, but in return they must both find their true human loves in 100 years or be exiled into the animal world alone. Although Alice has found her love, trickster Jim hasn't been able to commit to one woman until he sets eyes on free-spirited Bess, just before the deadline. Battling time and a meddling motorcycle seductress, the two new lovers must risk intimacy and loss in their quest for love.