I think this is the episode I loved less since the beginning of the show. There are two patients' stories; the first about a boy who's father was a black man and whose mother never told him the truth. The second is about a woman needing a surgery but having a drug addiction to be cure before and riskinh her life.
Christina seems to care much more for this patient than for her personal happiness. She is brave and she confesses to Bobbie her fear of a new relationship with a man who's not her husband. And I guessed this was the real reason for her hesitation about Tom.
But it is too strange to see a woman refusing a man like him twice, and I think he will be very upset for her behaviour.
Anyway, we'll see what's going to happen...