The old penal laws and the new ones were enforced with unusual severity. Courts were everywhere at work drawing up lists of recusants and assessing fines. Never before, even in the worst days of Elizabeth, were the wealthy Catholics called upon to pay so much. Numbers of priests were seized and conveyed to the coasts for banishment abroad; one priest was put to death simply because he was a priest, and two laymen underwent a like punishment because they had harboured or assisted priests. English Catholics were incensed at such pitiless persecution. Had it been inflicted by Elizabeth from whom they expected no mercy, it would have been cruel enough; but coming from a king, to whom they had good reason to look for toleration, and who before he left Scotland and after his arrival in London had promised an improvement of their condition, it was calculated to stir up very bitter feeling. Forgetful of the warnings of the Pope conveyed to the archpriest and the superior of the Jesuits, some of the more extreme men undertook a new plot against the king. The leading spirit in the enterprise was Robert Catesby, a gentleman of Warwickshire, whose father had suffered for his adhesion to the old faith. He planned to blow up the Parliament House at the opening of the session of Parliament when king, lords, and commons would be assembled. Hence his plot is known as the Gunpowder Plot. His followers had to be ready to rise when the results of this awful crime would have thrown the government into confusion. They were to seize the children of the king and to assume control of the kingdom. The scheme was so utterly wicked and impracticable, that it is difficult to understand how any man could have conceived it or induced others to join in its execution. Unfortunately, however, Catesby secured the assistance of Thomas Winter, Guy Fawkes, an Englishman who had served in the Spanish army, John Wright, Thomas Percy, cousin of the Earl of Northumberland, Sir Everard Digby, and Francis Tresham. A mine was to be run under the House of Commons charged with gunpowder, which Fawkes undertook to explode. An adjoining house was secured, and the cellar stretching under the Parliament buildings was leased. Everything was arranged for the destruction of the king, lords and commons at the opening of Parliament fixed finally for the 5th November 1605, but Tresham, anxious to save his brother-in-law, Lord Monteagle, sent him a letter warning him to absent himself on the occasion. By means of this letter the plot was discovered, and Guy Fawkes was arrested. The other conspirators fled to Wales, where they hoped to stir up an insurrection, but at Holbeche where they halted they were surrounded by the forces of the sheriff of Worcester. In the struggle that ensued Catesby and several of his followers, who defended themselves with desperate courage, were killed, and the remainder were put to death before the end of the month (Nov. 1605).