There was but one event which seriously broke the harmony of the tranquil life at Dalkeith, and that was the widespread Republican conspiracy of 1654. As Cromwell's most trusted officer Monk was one of its principal objects. In Morgan's absence the appointment of major-general on the governor's staff was held by Milton's friend, sweet-mannered Colonel Overton. The general shared the poet's high opinion of his honour, and had persuaded the Protector that his politics, radical as they were, would never make him forget his duty. This man accepted the management of the plot in Scotland. The idea was to assassinate Monk, seize the Government, and march with the Scotch army to the support of the English Republicans. To this end the army was widely tampered with, and as a matter of course the proceedings of the conspirators came to the vigilant general's ears. Quietly he allowed the plot to mature as if he suspected nothing, and then on the eve of its execution suddenly changed his guards, pounced upon the conspirators, and sent them all up to London under arrest. "I am convinced," he wrote to Cromwell in forwarding some papers of Overton's which he had subsequently discovered, "if your Highness do but weigh the letters well, you will find Colonel Overton had a design to promote the Scots king's business." Whatever was the part which the Cavaliers played in the plot, these letters certainly contain no evidence of their complicity. But Monk would believe anything of a soldier who had been false to his colours, and his comment is amusingly characteristic. It would seem that he had so little troubled himself with politics as to have entirely failed to grasp the situation. At this time he had probably got little beyond the original question of Parliament and King. Of the endless factions into which his own party was splitting he appears to have had but little understanding, except in so far as they led to insubordination in the army. Against a Royalist enemy he had been sent to Scotland, and he saw a Royalist enemy at the bottom of every trouble. Indeed it was at this time that he seems to have been first getting into that nervous and irritable state with regard to the King and his affairs from which he was never safe till Charles was on his throne. He was perfectly contented where he was. As the military governor of a conquered kingdom, he had reached the highest ambition of a soldier of fortune. He was now getting on for fifty, and desired nothing so much as to quietly enjoy his position with his wife and children, to whom he was devoted. Indeed, the death of George, the baby, about this time seems to have upset him more than all the difficulties of his office together. But his friends would not leave him in peace.