So great was the fear of treason and surprise that a strong force constantly held the gates, the guard-houses always containing about a thousand men, who permitted none to pass without a permit from the General. To protect the approaches of the town, strong outposts were maintained at Ste. Foye and Lorette; and on the other side of the river, at Point Lévi, a detachment of two hundred men held the south shore against surprises. As the winter wore away, it became increasingly evident that an attempt to recapture Quebec would not long be delayed. But although more than a thousand of the garrison were on the sick list, owing mainly to the tainted water of the wells, the laborious commandant kept good heart for the struggle, being in temperament cheerful, generous, and full of resource. Events proved, moreover, that he was daring even to the point of indiscretion. It was now March, and the campaign opened with a series of skirmishes round the newly-fortified English outposts. Sharp fights took place at Point Lévi and at Lorette; and Captain M'Donald, with five hundred men, even ventured as far up the river as St. Augustin to attack the strong post which Bougainville had established at Le Calvaire. Within the walls of Quebec, fever, dysentery, and scurvy grew so malignant that by the middle of April hardly more than three thousand men were fit for duty; and all the while evidence of the concentration of the French forces grew more apparent. So long before as the 26th of January, Lieutenant Montresor had been despatched over the snow with twelve rangers to apprise General Amherst of the plight of the city; and on the 21st of April the battered schooner _Lawrence_, the only craft upon which Murray could lay hands, was sent eastward to hasten Lord Colville's fleet when it should arrive in the river. Still, the vigilant defenders of Quebec were only half aware of the threatening danger; and even as the _Lawrence_ raced down the stream to bring help, the French army was advancing upon the city. Starting at Montreal in a fleet of bateaux, the forces of De Lévis and Vaudreuil had picked up the river garrisons as they advanced; and by the time they arrived at Pointe-aux-Trembles, their numbers had swelled to nine thousand men, while no word of their approach had as yet reached Quebec. On the night of the 26th of April, however, a remarkable incident brought timely warning.