Catelyn's "last" chapter has her and her son's revenue arriving at the Twins to marry Edmure to the (then) unknown Roslin Frey. Cat is really mistrusting of Lord Frey, totally unfounded mistrust, by the way, and so she tells Robb to keep his cool and seek protection from the Guest Right. The thing is, Walder, Roose and Tywin already have the best idea for a boyband in mind, and they think Robb is not going to let his subjects go to their opening concert next tuesday. So, they plan on murd