Count La Motte is the right person to entrust with the important load intended for the patriots of Fort Ontario … And Mark, Gancho, Mister Bluff and Gufo Triste will soon realize how true this is, even if one might justifiably be a bit perplexed when faced with the tiny and ever so light caskets the wily aristocrat hands over to them. It’is a good job that Flock intervenes to save the destiny of the Revolution … Many mysteries trouble the inaccessible peaks that crown the woods of Ontario. Why are the English engaged in constructing an outpost in that particular region ? What is contained in the casket that Mark cannot manage to seize from the hands of an officer of His Majesty ? And above all, who is the mysterious white woman whose word is law for the warlike Indians of these lands ?