The Book of Ashes — Jamie Mason

The Night Plague devastated humanity. Vancouver Island is a feudal wasteland ruled by the Hell's Angels. In a trailer by the forest, retired school teacher Cory O'Neal composes a history of the plague. But the more he writes, the more his history resembles a confession.

Beautiful, haunted Joanna Ward was the most brilliant and gifted student of Cory's career. During a troubled year in a dysfunctional private school, they forged a bond that led to accusations of improper conduct and Cory's departure. But in the intervening decades, Canada has become increasingly rocked by civil unrest. The RCMP suddenly evacuates Cory's town and a mysterious epidemic explodes from a lab where the adult Joanna works, leaving unsettling questions:
                 
What really happened between her and Cory that final year?
How does the rise of a sinister cult relate to the spreading chaos?
Will the events that ended Cory's career also end Mankind?