Marie de Sabrevois

The agent is Henri Guerlac de Sabrevois, a seigneur and captain in the Béarn regiment, a "devil with the women"[1] who watched Mary in Arundel with lascivious (and what we now called pedophilic) intent.

[1]: 142  This may be how she makes the acquaintance of the director of the Saint-Sulpice Seminary, who later proves to be a fanatical loyalist (anti-independence) spymaster, before Guerlac brings her back down to Québec City to resume their cohabitation.

Meeting this novel's narrator and his brother, Arundel men, she pretends never to have heard of the town and recasts for their benefit the late Guerlac as having been her father, whose property she has come to England to dispose of.

But there is a romantic, as well as political, bewitchment afoot: the victim in Rabble is not the narrator but rather his Harvard-educated and Loyalist brother, Nathaniel, whom she easily gets to take to America details of the coming imperial counterinsurgency expedition under General (and playwright) John Burgoyne.

His contact, and Marie’s second unwitting mule, is Ellen, at Hazen's chateau in Iberville, Quebec, where a close civilian eye may be kept on the rebels moving down the Richelieu via Fort Saint John.