Empire of Wild: Cherie Dimaline

Broken-hearted Joan has been searching for her missing husband, Victor, for almost a year - ever since he went missing on the night they had their first serious argument.
One hung-over morning she is drawn to a revival tent in a nearby town - and there is Victor. Only he insists he is not Victor, but the Reverend Eugene Wolff, on a mission to bring his people to Jesus.
With only two allies - her Johnny-Cash-loving, 12-year-old nephew Zeus, and Ajean, a foul-mouthed euchre shark with deep knowledge of the old Metis ways - Joan sets out to remind the Reverend Wolff of who he really is. If he really is Victor, his life and the life of everyone she loves, depends upon her success.