Can you summarize the story of Dev's Udyapan ceremony and Sai Baba's mysterious attendance?

During Dev's Udyapan ceremony, he invited Sai Baba, who promised to attend with two others. As Chapter 40 describes, a Sanyasi and two companions arrived uninvited, were fed, and then left. Dev, however, failed to recognize them as Baba and his party, feeling disappointed and deceived. He wrote to his friend Jog, who then consulted Baba. Baba confirmed that he had indeed come in the guise of the Sanyasi, fulfilling his promise exactly as stated. Upon learning this through a letter from Jog, Dev was overcome with love and regret for having doubted Sai and failing to recognize him due to a 'veil of Maya'.