They at once began constructing two large flat-bottomed boats of light enough draft to run the rapids in the flood-tide of spring. Carpenters worked hidden in an attic; but when the timbers were mortised together, the boats had to be brought downstairs, where one of the Huron slaves caught a glimpse of them. Boats of such a size he had never before seen. Each was capable of carrying fifteen passengers with full complement of baggage. Spring rains were falling in floods. The convert Huron had heard the Jesuits tell of Noah's ark in the deluge. Returning to the Mohawks, he spread a terrifying report of an impending flood and of strange arks of refuge built by the white men. Emissaries were appointed to visit the French fort; but the garrison had been forewarned. Radisson knew of the coming spies from his Indian father; and the Jesuits had learned of the Council from their converts. Before the spies arrived, the French had built a floor over their flatboats, and to cover the fresh floor had heaped up a dozen canoes. The spies left the fort satisfied that neither a deluge nor an escape was impending. Birch canoes would be crushed like egg-shells if they were run through the ice jams of spring floods. Certain that their victims were trapped, the Iroquois were in no haste to assault a double-walled fort, where musketry could mow them down as they rushed the hilltop. The Indian is bravest under cover; so the Mohawks spread themselves in ambush on each side of the narrow river and placed guards at the falls where any boats must be _portaged_. Of what good were the boats? To allay suspicion of escape, the Jesuits continued to visit the wigwams.[6] The French were in despair. They consulted Radisson, who could go among the Mohawks as with a charmed life, and who knew the customs of the Confederacy so well. Radisson proposed a way to outwit the savages. With this plan the priests had nothing to do. To the harum-scarum Radisson belong the sole credit and discredit of the escapade. On his device hung the lives of fifty innocent men. These men must either escape or be massacred. Of bloodshed, Radisson had already seen too much; and the youth of twenty-one now no more proposed to stickle over the means of victory than generals who wear the Victoria cross stop to stickle over means to-day.