The assailants were, in truth, impotent before the masterly inactivity of Carleton, who waited patiently behind his walls for the arrival in the spring of a British fleet. Counting upon this expectancy the Americans tried an old-time ruse. Between nine and ten o'clock in the evening of May 3rd, with the moon shining brightly and the tide flowing in and nearly high, a ship under full sail came into view from the direction of the Island of Orleans. With the wind behind her she swung in at a good rate of speed. Those who watched were, for a moment, sure that the long expected rescue had come. But, as she bore down to the cul de sac where lay the shipping at Quebec, she made no response to signals. At last, the British, after three vain efforts to draw a response, warned her to reply or they should fire. When this threat was carried out she was only some two hundred yards away. Then suddenly flames burst out on the ship, followed by random explosions; a boat left her side rowed very swiftly, and it was now apparent that she was sent to burn, if possible, the British shipping. It must have been an anxious moment when she was so near and heading straight for her prey. But, showing a natural prudence, those who steered left her too soon and, with no hand at the helm, her head came up quickly in the wind. By this time all Quebec had been alarmed and, as attack from the landward side was also expected, every man was soon at his post. The ship was a striking sight as, with sails and rigging on fire, she drifted helplessly before the town. When the tide turned she floated down, a mass of fire, with explosions shaking her from time to time, to the shallows off Beauport where she soon lay stranded, a blackened ruin of half-burnt timbers.

Quebec still waited for rescue, and not in vain. At day break, on the 6th of May, a frigate appeared round Point Levi. Again went forth the cry of "A ship," "A ship." "The news," we are told, "soon reached every pillow in town." Men half dressed rushed to the Grand Battery, which was quickly crowded with spectators, who indulged in much shaking of hands, and in the exchange of compliments, as the character of the ship became clear. She was the British frigate Surprise, and, with much difficulty, had forced her way, under full sail, through the great fields of ice which still blocked the river. Following her closely were the Isis and a sloop the Martin. Quebec went wild with joy. But there was still serious business on hand. The Surprise brought a part of the 29th regiment and a good many marines. They were landed at once. Carleton lost not a moment and, by twelve o'clock of the same day, the gates of Quebec were thrown open and he marched out to attack the Americans.

It was only a thin red line that stretched across the Plains of Abraham. But the Americans dared not face it. The newly arrived ships might, they feared, carry a force up the river and cut off retreat; so, after some desultory skirmishing, the investing army fled. It was now commanded by General Wooster, for Arnold had gone to Montreal. The flight soon became a panic. Arms, clothes, food, private letters and papers were thrown away. Nairne was in command of a portion of the Highland Emigrants, who were the vanguard of the British pursuing force, and was among the first to occupy the American batteries. On that very ground he had fought, victorious in 1759, woefully beaten in 1760; now, a victor again, he helped to drive back a force, some of whose members had been his companions in those earlier campaigns. That night the relieved British slept secure in Quebec, while the bedraggled American force was making its distressful way towards Montreal.

Though the American army soon withdrew from Montreal and from Canada, the war was still to drag on for many weary years. Throughout the whole of it Nairne remained on active service. In September, 1776, we find him in command of the garrison at Montreal. In 1777 he was sent to command the post at Isle aux Noix which guarded the route into Canada by way of Lake Champlain. Here Fraser was serving under him as Captain; the two friends were usually together throughout the war. At Isle aux Noix Nairne remained until June, 1779. We get glimpses from his letters of the defects in the service at this time. There were involuntary evils, such as scurvy, caused by want of fresh meat and vegetables, but relieved by drinking a decoction of hemlock spruce. Moral evils there were too, such as gambling and drunkenness; in 1778 the commanding officer gave warning that he had heard of losses at play, and that those taking part in such practises would be excluded from promotion.

The British officers showed sometimes a fool-hardy recklessness. On March 9th, 1778, one Lieutenant Mackinnon, with forty-five volunteers, set out from Pointe au Fer, near Isle aux Noix, to surprise an American post at Parsons' House, no less than sixty miles distant, and in the heart of the enemy's country. A few days later two of the volunteers returned with news that the attack had wholly failed, that six of the party were killed and six wounded, and that Lieutenant Mackinnon and four others were missing. So reckless an attack was bad enough and, in the General Orders, it was condemned as "a presumptuous disregard of military discipline"; only vigilance and watchfulness were required of the picket at Pointe au Fer, so that the enemy might not invade the province. At the incident the Commander-in-Chief was very angry. "I never saw the General in such a passion in my life," wrote an officer to Nairne. Mackinnon had surrounded the house in the darkness and both he and his men, as far as is known, had done their best. Though wounded and for a time missing, in the end Mackinnon got back crippled to Isle aux Noix. But he had failed, and whispers soon began that he showed cowardice in the attack; an absurd charge, as Nairne said, for he had given proof of rather too much, than of too little, courage. The accusation gave Nairne infinite trouble. The subalterns in the Royal Highland Emigrants refused to do duty with Mackinnon, and General Haldimand, who succeeded Carleton in the summer of 1778, would not take the matter seriously enough to grant a Court Martial, that Mackinnon might clear himself. For quite a year and a half the affair dragged on. In the end, at a Court of Enquiry, Mackinnon was acquitted. Haldimand told Nairne to rebuke the officers sternly for combining to subvert authority, for disrespect to their superiors, and for refusing, on the basis of futile reports and hearsays, to serve with Mackinnon. "I much mistake his character," wrote Nairne of Mackinnon, "if he can ... be prevented from calling one or two of those gentlemen to a severe account."

A part of Nairne's duty was to watch the French Canadians and check sedition. In spite of the failure of Arnold's expedition many of them were still favourable to the American cause. They harboured deserters in the remoter parishes, gave protection and assistance to rebels, and threw as many difficulties as possible in the path of loyalists. Nairne found two men issuing papers from a printing press to foment sedition and sent them down to Quebec to stand their trial for treason.

From Isle aux Noix Nairne was sent, in the summer of 1779, with fifty of his Royal Highland Emigrants, to command at Carleton Island, near Kingston where Lake Ontario flows into the St. Lawrence; some thirty-five years later his only surviving son held a military command at the same place. Here there was much to do in strengthening the fortifications and in keeping up communications with Niagara and other points in the interior. The situation was not without its embarrassments. Prisoners were sent in from Niagara and he had no prison in which to keep them. For want of fresh meat and vegetables there was much sickness. But the Indians were his greatest trial. Through him came their supplies and, to hold them at all, he had sometimes to serve out the rum for which such savages are always greedy. On July 4th, Nairne made a speech to these Mississaga Indians and said pretty plainly what he thought of them. Against the American scouts they had proved no defence; at night they fired off guns in the neighbouring woods and created false alarms, which prevented Nairne's men from getting their proper sleep. "My men work hard in the day," he said, "and I will have them to sleep sound at night," and he warned the Indians that he would fire upon them if their noise disturbed him further. The savages, he wrote to Haldimand, are "almost unbearable, greedy and importunate." They behaved more like rebels than friends and their talk ended always in the demand for rum, "the cause of all bad behaviour in Indians."

On the remoter frontiers the war was ruthless beyond measure. Sir John Johnson devastated the Mohawk valley, in the present State of New York, and some of his prisoners were received at Carleton Island. Of this inglorious warfare Haldimand's secretary, Captain Matthews, wrote to Nairne a little later [17th June, 1780], "You will have heard that Sir John Johnson has executed the purpose of his enterprise without the loss of a man, having destroyed upwards of an hundred dwelling houses, barns, mills, stock, &c., and brought off 150 Loyalists, besides Women and Children." The worst outrages came from the Indian allies, of whom Nairne thought so badly. From Niagara, on March 1st, 1779, Captain John MacDonnell wrote to Nairne of the terrible massacre at Cherry Valley, on the New York frontier, which excited horror throughout the colonies, and did much to inflame the hatred of the Americans for England. Not, however, the English but the Indians were really guilty. "There has nothing appeared," wrote Captain MacDonnell, "on the theatre of the war of near so tragical or rather barbarous a hue; the reflection never represents itself to my view but when accompanyed with the greatest horrors; both Sexes, young and old Tomahawked, Speared and Scalped indiscriminately in the most inhuman and cruel manner. But that there was all possible care and precaution taken to prevent them is undenyable. Captain Butler, who had command of the expedition, was indefatigable in his endeavours and exertions to restrain and mitigate the fury and ferocity of the savages often at the risk of the Tomahawk being made use of against himself as well as the Indian officers.... Out of a hundred and seventy scalps three-fourths were those of Women and Children." Butler's name is still looked upon in the United States as that of a fiend incarnate, but the testimony of his fellow officer seems to free him from blame for the worst of the horrors. Both sides were bitter, but Nairne himself never shows any vehemence of passion. In his view the war was a painful necessity, to be fought to the end without anger.

Late in 1779, Nairne was recalled from Carleton Island. He reached Montreal on the 5th of December, and, two days later, secured leave of absence to look after his private affairs. At this time General Haldimand had matured a plan to take advantage of the remote position of Murray Bay to confine there some of his American prisoners. At Murray Bay they seemed particularly safe. There was as yet no road over Cap Tourmente; in any case to go in the direction of Quebec would mean seizure sooner or later; to go in the opposite direction would be to perish in the wilderness; and the only outlet was by water across a wintry river some twelve miles broad. On the 26th of January, 1780, Haldimand wrote to Nairne at Murray Bay that he was to erect buildings for rebel and other prisoners, and that, to do the work, some men were being sent down; he was to employ in addition as many of the inhabitants as he might think necessary.

Nairne stayed on at Murray Bay in 1780 much longer than the two months for which he had originally asked. A part of his duty was to watch that American colony, so different in station and situation from the many Americans who now visit the spot. As yet there were no barracks in which to confine the poor fellows, and the climate of Murray Bay is not too hospitable in winter. Some kind of rough quarters must have been prepared for the prisoners, in the winter of 1779-80, and they were kept busy in helping to build the houses intended for their occupation. They seemed contented. One of them Nairne kept about his person. He knew where everything was placed and all the men were used, Nairne says, in the best manner he could think of. But liberty is sweet and they longed for their own land. So, early in May, 1780, when the ice was out of the river and there was a chance to get away, eight of them made a dash for liberty.[11] No doubt under cover of night, they stole a boat and put out boldly into the great river across which, in so small a craft, few ever venture, even in mild summer weather. Almost wonderful to relate, they reached the south shore in safety. Nairne was uncertain whether they had gone up, down, or across the river. He hurried to Tadousac, crossed to Cacouna and then went up the south shore. At St. Roch he found that the men, rowing a boat, had been seen to pass. On May 14th this boat was found abandoned. On the 15th the men were seen on the highway carrying their packs. We are almost sorry to learn that the poor fellows were in the end captured and taken to Quebec. Nairne reported the flight of these men on the 14th of May. Their example was contagious for, on the 18th, while he was absent in their pursuit, four others made off, found a small boat on the shore some nine miles from Malbaie, and put out into the river, where their tiny craft was seen heading for Kamouraska on the south shore. A few days later two others also escaped. These had not courage to strike out into the river, and one of them was caught at Baie St. Paul. Nairne offered a reward of four dollars for each of the prisoners and probably all were taken. A sequel of the incident was that a non-commissioned officer and eight men of the Anhalt-Zerbst Regiment were sent to guard the remaining prisoners at Murray Bay—a task apparently beyond Nairne's local militia. This guard was, no doubt, composed of Germans; one wonders to what extent they fraternized with the French Canadians. It is amusing to read that, when one of them deserted, he was brought back by a habitant.