Not another Stark

- It was a random useless (plotwise) book - It was a book about lineages, indeed; maybe the book Ned - or was it Jon Arryn, or both? - read about weddings between Lannisters and Baratheons - important plotwise as it's directly related to the current Westerosi warfare - It was a book about ancient lore, the threat looming beyond the Wall, PTWP, Others, that kind of things / alternatively, a book about dragons - something important plotwise, but that would involve Boltons way beyond the mere civil war in Westeros Concerning Theon: Ramsay may just want to have him at his side, instead of leaving him behind. Asha's still around, there may still be some Stark followers, he might know about Stannis. All in all, even if an assault on Dreadfort wouldn't work, he might think it's too risky to leave such a precious hostage there. He may also wants to use him during the reconquista over the Ironborn. Last but not least, does Ramsay has any reason to doubt Arya's true identity? Roose probably has suspicions, but would he share them with Ramsay? Could it be that Roose had no intention of mentioning to Ramsay that he was to marry a fake Arya? Could Theon notice that she isn't Arya and mention it to Ramsay - without this being the reason Ramsay took Theon with him? And if Ramsay was totally unaware of this, could he be upset and feel cheated and betrayed by his dad, could this make him off Roose - not because he planned it all along but was suddenly pissed off? (not that Roose being killed is a given, mind you, I consider this as wild speculation)