Nolan was unable to obtain any more passports from the Spanish authorities. He conceived or borrowed a scheme to go illegally into Texas and perhaps other Mexican provinces. There is considerable dispute about the exact nature of this filibustering expedition; some claim that he promised his men that they would seize riches and land and create a kingdom for themselves. In any case, he convinced some thirty frontiersmen that the expedition would make them rich. They crossed the border in October 1800 and headed north of Nacogdoches to capture wild mustangs. The Spanish soon heard of their activities, and Pedro de Nava ordered their arrest.