Time After Time
Season 3 | Episode 20 | Aired 04/19/07
Colin Marlow asks Cristina to assist him on a "piggyback" heart transplant and grudgingly says that Burke can also scrub in. Cristina decides she must treat Colin's continued pursuit of her like a chess match, and outflank him. She plays up her affection for Burke in front of him, holding hands, showing off the nail colors she's trying out for the wedding. We know. It’s weird.
Colin sees right through her little game. It's only when he catches her asking Burke a surgical question that he knows she already knows the answer to, that he realizes he's seeing their true relationship. The Cristina he knew would never stoop to building up a man's ego. He says there's no point in pursuing the Chief position here since the woman he knew is gone. Back at home, Burke says he's relieved she can now go back to "the real Cristina," but it's obvious that Cristina isn't so sure who that is.