We learn that the old man is actually Wenyao's grandfather, and that he's been practicing medicine in London for a long time. He's also got a Ph.D. in medical sciences from Oxford, which means that he knows how to diagnose and treat diseases. He tells us that his grandfather is trying to swindle him out of money by telling him that his wife's condition is an "undiagnosed disease" . We learn, however, that this isn't the first time that this sort of thing has happened. In fact, it's just the tip of the iceberg.