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Addison says that if the baby doesn't come within an hour, there may not BE a baby. The chief of staff starts having what looks like a heart attack (and they say something to that effect, like "he's having a heart attack") Christina sticks her head into Derek's O.R. and he says "how is the girl with the bomb?" and she says "it's Meredith, the girl with the bomb is Meredith", and Derek jerks his head around.