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 inciting a popular revolt to install James's daughter, Princess Elizabeth, as titular Queen. To this end he had already helped enlist nine Catholics into the conspiracy, but was running out of money and needed to recruit more men. Rookwood was a horse-breeder, and his stable of fine mounts at Coldham Hall was needed for the Midlands uprising. He had been asked to supply them with gunpowder about a year earlier, under the pretence that it was for William Stanley's regiment in Flanders—no longer an illegal operation due to the recent Treaty of London—but otherwise provided no funds for the conspiracy.