As my combined Feast/Dance re-read reaches the homestretch, the one crackpot theory I’m warming to a bit is the idea that Theon/Reek is killing people in Winterfell during dissociative episodes late at night. I always thought the lords were correct in their assessment that he was physically and emotionally incapable of violence anymore, but in the chapter featuring his escape with Jeyne/Arya he clearly has to hold himself back from murdering Rowan the washerwoman, and later picks Jeyne up and carries her over his shoulder while fleeing from the guards. Hell, maybe the mysterious man he meets really IS his alternate personality — I thought the fact that the man calls him “kinslayer” ruled this out given that Bran and Rickon were neither Theon’s kin nor actually slain, and Theon of all people should know this when talking to himself, but perhaps a part of Theon thinks/knows that the miller’s wife’s sons he really did kill were really his own offspring?