The siege continued to drag on slowly, when about the end of March, 1571, a man named Robertson, who had formerly belonged to the garrison, but who wished to be revenged for some punishment inflicted on his wife, suggested a plan for taking the Castle by surprise. It was adopted, and Captain Thomas Crawfurd of Jordanhill was entrusted with the desperate enterprise. On the evening of the 31st, Crawfurd sent forward some horsemen to intercept all communication with Dumbarton, he himself following about midnight with a body of resolute men. After a short halt at Dumbuck, the party, provided with ropes and ladders, proceeded to the foot of the Rock, which was to be scaled at the "Beik", for although this was the highest point, it offered the advantage of being unguarded, by reason of its supposed inaccessibility. At the first attempt the ladder slipped back with the weight of the climbers. On the second it was found that it did not reach within twenty feet of a tree to which it was intended to make it fast. The difficulty was overcome by Crawfurd, who, crawling up to the tree, threw a rope around it, and thus enabled his party to reach this first stage. The operation was being repeated for a further ascent when an accident nearly brought disaster on the whole undertaking. One of the men fell into a kind of fit whilst on the ladder, and remained clinging desperately to the rungs and blocking the way. But, even for this, Crawfurd's readiness devised a remedy. Lashing the man to the ladder, he turned it round, so that the remainder of the party could mount over their comrade's upturned body. Owing to the delay caused by these untoward occurrences, it was nearly daylight when the first of the assailants reached the top. They were seen by the sentries through the fog, which had so far favoured them, and the alarm was given. The resistance offered was, however, but feeble. Three men of the garrison were killed. Many of the others, including Fleming himself, succeeded in escaping. Amongst those that were taken prisoners was the Bishop of St. Andrews. He was subsequently hanged for complicity in the murders of Darnley and of Murray.[242]