Robert and Thomas Wintour is written about the Gunpowder Plot is derived from Thomas's confession, signed on 23 November 1605; details of the so-called Spanish Treason were added three days later. One of only two confessions printed in the "King's Book" (a highly partial contemporary account of the affair), Thomas Wintour's was the only account the government had of a plotter who had been involved from the beginning; Guy Fawkes, weakened by days of torture, may have been at the heart of the group, but he was not at its first meetings. However, Antonia Fraser views the document with suspicion, not least because Thomas's
Stephen Lyttelton chose to fly on his own and he urged Wintour to do the same. Wintour did not listen to him but proceeded to Holbeche House, where he saw that the conspirators were alive, but some of them were injured. Robert Wintour was one of the conspirators who fled from Holbeche House the night between 7 to 8 November and he met up with Littleton shortly thereafter. On January 9, 1606, they both were arrested. They had spent two months on a flight where they were hiding in barns and houses and at one time they had to block a drunk