How It All Goes Down
Catelyn 9
- Robb needs to get his army across the Green Fork river and the only place he can do that is at the Twins, a bridge controlled by Lord Walder Frey (and protected by two identical castles on either side, hence the name "the Twins").
- Although Frey is sworn to Hoster Tully, he's not the most trustworthy person, says Catelyn. Still, they have to negotiate, and since she knows Walder, she'll go talk to him.
- Walder Frey is old and bitter: he's angry at (seemingly) every lord who ever slighted his house (which is all of them). He also has a lot of kids.
- Catelyn returns to Robb with terms that include taking on one Olyvar Frey as a squire and marrying another Frey – whichever one Robb wants to marry. (Oh, and Arya is supposed to marry another, if she's still alive.)
- For that, Walder will join his army to Robb's and let them pass over his bridge. (Can you imagine if all toll bridges involved this kind of trade?)