A plot was on foot to seize Pitt, Niagara, and Detroit.

Seneca ambassadors had visited the Wyandots in the vicinity of Detroit, urging them to fall on the garrison.

After an investigation, Captain Campbell reported to Amherst that an Indian rising was imminent, and revealed a plot, originated by the Senecas, which was identical with that afterwards matured in 1763 and attributed to Pontiac's initiative.

Campbell warned the commandants of the other forts of the danger; and the Indians, seeing that their plans were discovered, assumed a peaceful attitude.
Still, the situation was critical; and, to allay the hostility of the natives and gain their confidence, Amherst dispatched Sir William Johnson to Detroit with instructions 'to settle and establish a firm and lasting treaty' between the British and the Ottawa Confederacy and other nations inhabiting the Indian territory, to regulate the fur trade at the posts, and to settle the price of clothes and provisions.

He was likewise to collect information as exhaustive as possible regarding the Indians, their manners and customs, and their abodes.
He was to find out whether the French had any shipping on Lakes Huron, Michigan, and Superior, what were the best posts for trade, and the price paid by the French for pelts.