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
Robert and Thomas Wintour friends also would with good reason condemn us." He nevertheless agreed to join the conspiracy, and as Catesby had not entirely given up hope of foreign support—"because we will leave no peaceable and quiet way untried"—Thomas returned to the continent. In Flanders he met Juan Fernández de Velasco, 5th Duke of Frías and Constable of Castile, who was holding court there before his journey to England to conclude the Treaty of London. Thomas again stressed the plight of English Catholics, hoping to influence the forthcoming treaty negotiations due to take place at Somerset House in London. The Constable was "friendly