They've been a touch inconsistent with that. Sometimes it seems like they're just meeting in a random non-sequential order, and sometimes it seems like they're meeting in a specifically opposite-directions order. But there's too many examples that make the "opposites" option impossible, so we can only rationalise it by saying it must actually be the "random" order, no matter what some people sometimes describe it as.I thought I heard in an episode this season that River and the Doctor are meeting in reverse order. River's past is the Doctor's future and vice versa. Shouldn't the first time River meets the Doctor be the last time the Doctor meets River?
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