With Sally at home with the new baby, Mac is happy to entertain his mother, Beatrice, who has come to San Francisco for a visit. She has some big news: his sister Megan is getting married. Beatrice likes the young man but Mac's quick check of his background reveals that he has a manufactured identity and history. When he confronts him, he admits to being Randy Murphy and claims to have changed his name and history to hide his working class background from them - though not Megan - so they wouldn't think less of him. He does, however, seem to be keeping secrets and ...