The Red Wedding was the most highly anticipated event of Game of Thrones Season 3. But what is this plot-changing moment from Season 3, Episode 9: "The Rains of Castamere"?
The Red Wedding was the wedding of Catelyn's brother, Edmure Tully, to Roslin Frey; more specifically the aftermath of said wedding. As we saw in Season 3, Episode 6: "The Climb," this marriage took place ostensibly so Robb Stark could win back the support of Walder Frey after Robb backed out of his own engagement to one of Walder's daughters in favor of marrying Talisa. It turns out, Walder was not appeased.
Instead of allying himself with the Starks again, Walder teamed up with Roose Bolton and the Lannisters and stabbed Robb in the back. He waited until them after Edmure had wed Roslin and gone of to bed her (securing the marriage), and then attacked Robb and his army out of nowhere. Robb, Cat, and almost all of Robb's army were slaughtered. (Get a full recap of exactly what happened.)
So, what happens next? Here's where the Starks stand now. Plus we have spoilers about if there's any hope for seeing Robb or Cat again, based on the books.
The Red Wedding aired on Season 3, Episode 9: “The Rains of Castamere.”