Mordaunt, in spite of his youth and the ardent enthusiasm which had goaded the inert Knot into taking up the movement, had a clear head. In his heart he knew that much more was to be done by gaining the leaders of the Opposition than by the best planned risings, and for him Monk's adhesion, or at least his neutrality, was of the first importance. By the whole of the King's councillors, however, the general, to his honour, was looked upon as unapproachable. It was in this difficulty that his sanguine young cousin saw the opportunity for which he had been so long preparing, and declared himself ready to undertake the task. At his request he was armed with an effusive letter from Charles to Monk, and a commission leaving him free to treat, with the sole limit that no more than a hundred thousand pounds a year was to be promised to the general and his officers. Grenville lost not a moment, and a few days later poor book-loving Nicholas was startled in his quiet Cornish rectory by a peremptory summons to London. Monk's warning was not the only one which reached the Council. Sir Richard Willis, the most trusted member of the Knot and an old friend of Monk's, was revealing everything but the names of the Cavaliers engaged. The only anxiety of the Government was to conceal its information from the conspirators. At every point it was ready. Lambert and Fleetwood were old hands at the work. Their idea apparently was to allow the rising to take place, tempt the King to land, and then inflict a blow which would at once crush their adversaries and give themselves an unassailable prestige. Amongst other precautions Monk was ordered to send two regiments of horse and two of foot into England, and it is significant that he obeyed without demur. At the last moment an officious postmaster spoilt all. In a fit of zeal he intercepted an important letter. The Royalists got to hear of it, lost their heads, and the rising was nipped in the bud, or abandoned everywhere but in Cheshire and Lancashire. There Sir George Booth successfully established himself, and Lambert marched against him. Amidst the din and bustle of military preparation Nicholas Monk arrived in London, and with no little alarm heard from Grenville's lips what was required of him. Ostensibly for the purpose of settling his daughter's marriage, and bringing her back to Cornwall, he was to carry the King's letters to his brother and negotiate the secret treaty. Nicholas flatly refused to touch the letters. They were far too dangerous. He consented, however, to carry a verbal message, and was solemnly sworn not to breathe a word of the very delicate affair to any one but his brother.