The next date of interest this year (1658) is that of April 3rd, "when," says Dollier de Casson, "fifty Frenchmen reached here under the command of M. Dupuis, with the Jesuit fathers who had been forced to leave the mission of Onondaga for fear of being burned alive by the Iroquois. Several of their people, less disposed than they to death by being burned alive, as well as to any other kind which Providence might please to send, had such a fright that they were only cured when they came in sight of Montreal, a like miracle occurring here several times." This is the sequel of the letters sent by Maisonneuve, and its story must be told. The letters were not delivered, but instead the treacherous Indian messenger told the Onondagas that the French had just allied themselves with the Algonquins to make war against them. This angering the Onondagans, they concerted with the Mohawks and a delegation went to Quebec, arriving on January 3, 1658, to demand the return of their twelve prisoners detained as hostages. But M. d'Ailleboust gave them little satisfaction and they departed in February. In the same month a secret gathering was held, at Agnié of a few of the most influential heads of all the Iroquois nations, and there was sworn a war of extermination of the whites if their captives were not returned, and they would commence with the settlement of the black robes at Onondaga, which had been settled with them at their own invitation in 1656. A Christian Iroquois revealed this plot to the missionaries at Onondaga and these communicated it to Quebec. But how to escape from their own impending slaughter, the like of which had been witnessed on August 3, 1657, when seven Christians had been slain, by these same Onondagas before the horrified eyes of Father Ragueneau, then on his way, to be similarly repeated when, on reaching Onondaga, some of the Christian captives were burned, including several women and their infant children.