At this critical juncture, when the military skill and wisdom of the dispositions made by Wallace became apparent, and when the moment to harass and destroy the invading army in its retreat had arrived; the treachery of her nobles again betrayed Scotland. Two Scottish lords, Patrick earl of Dunbar, and the Earl of Angus, privately, at day-break, sought the quarters of the Bishop of Durham, and informed him that the Scots were encamped not far off in the forest of Falkirk. The Scottish earls, who dreaded the resentment of Edward, on account of their late renunciation of allegiance, did not venture to seek the king in person. They sent their intelligence by a page, and added, that having heard of his projected retreat, it was the intention of Wallace to surprise him by a night attack, and to hang upon and harass his rear. Edward, on hearing this welcome news, could not conceal his joy. "Thanks be to God," he exclaimed, "who hitherto hath extricated me frem every danger! They shall not need to follow me, since I shall forthwith go and meet them." Without a moment's delay, orders were issued for the soldiers to arm, and hold themselves ready to march. The king was the first to put on his armour; and, mounting his horse, rode through the camp, hastening the preparations, and giving orders in person, to the merchants and sutlers who attended the army to pack up their wares, and be ready to follow him.
At length all was prepared, and at three o'clock the whole army was on its advance from Kirkliston to Falkirk, astonished at the sudden change in the plan of operations, and at the slow and deliberate pace with which they were led on. It was late before they reached a heath near Linlithgow, on which they encamped for the night. They were not allowed the refreshment of disarming themselves; but, to use the striking words of Hemingford, "each soldier slept on the ground, using his shield for his pillow; each horseman had his horse beside him, and the horses themselves tasted nothing but cold iron, champing their bridles." In the middle of the night a cry was heard. King Edward, who slept on the heath, whilst a page held his horse, was awakened by a sudden stroke on his side. The boy had been careless, and the horse, in changing his position, had put his foot on the king as he slept. Those around him cried out that their prince was wounded; and this, in the confusion of the night, was soon raised into a shout that the enemy were upon them," so that they hastily armed themselves, and prepared for their defence. Butthe mistake was soon explained. Edward had been only slightly hurt; and as the morning was near, he mounted his horse, and gave orders to march. They passed through Linlithgow a little before sunrise; and on looking up to a rising ground, at some distance in their front, observed the ridge of the hill lined with lances. Not a moment was lost. Their columns marched up the hill, but on reaching it, the enemy had disappeared; and as it was the feast of St Mary Magdalene, the king ordered a tent to be raised, where he and the Bishop of Durham heard mass. These lances had been the advanced guard of the enemy; for while mass was saying, and the day became brighter, the English soldiers could distinctly see the Scots in the distance arranging their lines, and preparing for battle.