Gate of Darkness, Circle of Light — Tanya Huff

THE WILD MAGIC
was loose in Toronto, for an Adept of Darkness had broken through the barrier into the everyday mortal world. And in this age when only fools and innocents still believed in magic, who was there to fight against the invasion by evil?

Luckily--or perhaps by more than luck--Toronto did have some unexpected champions of the Light: Rebecca, who some called simple yet who was gifted with the Sight; Roland, a street musician who might one day be a Bard; Mrs. Ruth, a bag lady with some unexpected tricks in her bags; Daru, an overworked social worker with a case load that mushroomed as rapidly as the power of the Dark; Tom, a cat of rare vision and courage; and Evan, Adept of the Light, summoned to stand with these mortals in the desperate battle to keep the Earth from falling into final, total Darkness....