The day this letter was written in Boston, May 6, Warren had already begun the regular blockade. Only a single ship eluded him, an ably handled Basque, which stood in and rounded to, under the walls of Louisbourg, after running the gauntlet of the Royal Battery, on which the French fired with all their might to keep its own fire down. A second vessel was forced aground. Her captain fought her to the last; but Warren's boat crews took her. Some men who escaped from her brought du Chambon the news that a third French ship, the Vigilant, was coming to the relief of Louisbourg with ammunition and other stores. This ship had five hundred and sixty men aboard, that is, as many as all the regulars in Louisbourg. On May 31 the garrison heard a tremendous cannonading out at sea. It grew in volume as Warren's squadron was seen to surround the stranger, who was evidently making a gallant fight against long odds. Presently it ceased; the clustered vessels parted; spread out; and took up their stations exactly as before, except that a new vessel was now flying the British flag. This was the Vigilant, which had been put in charge of a prize crew, while her much-needed stores had been sent in to the Provincial army. The French in Louisbourg were naturally much discouraged to see one of their best frigates flying the Union Jack. But they still hoped she might not really be the anxiously expected Vigilant. Warren, knowing their anxiety, determined to take advantage of it at the first opportunity. He had not long to wait. A party of New Englanders, wandering too far inland, were ambushed by the French Indians, who promptly scalped all the prisoners. Warren immediately sent in a formal protest to du Chambon, with a covering letter from the captain of the Vigilant, who willingly testified to the good treatment he and his crew were receiving on board the British men-of-war. Warren's messenger spoke French perfectly, but he concealed his knowledge by communicating with du Chambon through an interpreter. This put the French off their guard and induced them to express their dismay without reserve when they read the news about the Vigilant. Everything they said was of course reported back to Warren, who immediately passed it on to Pepperrell.