The Cure for Drowning by Loghan Paylor

Evocative, magical and luminously written, The Cure for Drowning is not only a brilliant, boundary-pushing love story but a Canadian historical novel that boldly centres queer and non-binary characters in unprecedented ways.

Born Kathleen to an immigrant Irish farming family in southern Ontario, Kit McNair has been a troublesome changeling since, at ten, they fell through the river ice and drowned—only to be nursed back to life by their mother's Celtic magic. A daredevil in boy's clothes, Kit chafes at every aspect of a farmgirl's life, driving that same mother to distraction with worry about where Kit will ever fit in. When Rebekah Kromer, an elegant German-Canadian doctor's daughter, moves to town with her parents in April 1939, Rebekah has no doubt as to who 19-year-old Kit is. Soon she and Kit, and Kit's older brother, Landon, are drawn tight in a love triangle that will tear them and their families apart, and send each of them off on a separate path to war. 

Landon signs up for the Navy.