Continuity mistake: Possible Spoilers! At the very end of the episode Rick walks up to the wall of Alexandria to check out a noise. When the camera shows the walker on the other side of the fence it is clear there is nothing else out there. When the camera shows the fence from behind Rick there is the roof of a house visible above the top of the fence. The shadows made by the struts of the fence make it apparent that if there was a house the other side of the fence would have been in shadow.
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