Malcolm Archibald 
Edge Of Reason [EPUB ebook] 

Canada, 1759. After the capture of Quebec in the Seven Years War, Corporal Hugh Mac Kim of the 78th Highlanders attempts to desert the British army. But when Hugh is caught in an ambush, his loved one, Tayanita, is mortally wounded by a tall, tattooed Canadian.
Mac Kim swears vengeance. Suffering from nightmares, he returns to the army, transfers to the Rangers and decides to fight in a series of skirmishes through the winter. When the French attacks on the British outposts become more frequent, General Murray organizes the Flying Picket: a group of men dedicated to preventing the French attacks.
Certain that his sworn enemy, Lucas de Langdon, is among the attackers, Mac Kim joins General Murray’s group. But can he exact his revenge, and has the strain of war tipped him over the edge of reason?