What did Narcisco do when he realized he would not be able to get to the Marez home to warn Ultima of Tenorio's revenge?

Antonio worried he may have revealed his secret during his delirium. Ultima reassured him that he hadn't. Even at a young age, Antonio showed signs, of his ability to keep secrets, of being the priest (the confidante), that mother wanted him to be. He was being "groomed" for this position.