Robert and Thomas Wintour the continent and again failed to elicit Spanish support, but instead met Guy Fawkes, with whom he returned to England. Robert, a devout Catholic who inherited Huddington Court near Worcester, joined the conspiracy the following year. The plot began to unravel following the delivery of an anonymous letter to William Parker, 4th Baron Monteagle, warning him to stay away from Parliament. Thomas and Catesby confronted Monteagle's brother-in-law, the recently recruited Francis Tresham, threatening to kill him, but Tresham managed to convince them of his innocence. At that stage Thomas reportedly asked Catesby to abandon the scheme, to no avail. When
Ambrose Rookwood Catesby and Percy were reportedly both killed by a single musket ball. Rookwood was also shot, but survived and was quickly captured. His belongings should by right have been seized by the government, but his elaborate sword apparently proved to be too great a temptation for the Sheriff's men, and disappeared without trace. Rookwood and the others were taken first to Worcester, and then to the Tower of London. Those conspirators still at large were rounded up shortly after. Watched in secret by the king and his family, the surviving conspirators were arraigned in Westminster Hall on 27 January 1606.