Last night's Game of Thrones finale was a very satisfying cap to a very satisfying fourth season, concluding with a poetic shot of Arya Stark on a Braavos-bound boat that felt like a fitting conclusion to the year's story arcs. But if you were watching with a fan of the books, the subsequent cut to black probably had them screaming "WAIT, WHAT!?" A key scene that concludes the third book, A Storm of Swords, from which this season has largely drawn, was missing. Were the showrunners right to exclude it?
Now, be warned: read on only if you've read the books, or do not care about spoilers regarding this final scene, which, to be sure, is a real doozy.
The epilogue of A Storm of Swords sees a member of the Frey family who participated in the Red Wedding taken captive by the Brotherhood Without Banners. You remember them—the outlaw bandits who fight for justice against the Lannisters, led by the one-eyed Beric Dondarrion and his red priest Thoros, who somehow has the power to revive him every time he's killed. Then it's revealed that Beric is gone and has passed his powers of revival to someone else—Catelyn Stark, reincarnated as a silent, zombie-like specter who passes judgment against those that did her wrong.
She's now named "Lady Stoneheart" and has assumed control of the Brotherhood, with the single-minded goal of destroying all those that have wronged her. It's a dark, shocking note to end the book on, but it's not unsatisfying, and visually of course it would have been a jarring and powerful final image for the show to end the year on. Lena Heady (who plays Cersei) had obliquely teased things with a much-discussed Instagram two months ago.
There's no official word on why the show's creators decided to omit this scene, and there may never be—David Benioff and D.B. Weiss have never been particularly interested in discussing the changes they're making to the source material. It's very plausible that they're saving the reveal for season five, since this season has been entirely lacking in Catelyn; maybe the writers thought including her at the end would be too jarring. Arya's escape to Braavos is, in a way, a more uplifting conclusion, and Catelyn's return can be used as a punchy conclusion to an early episode next year. Plus, there were plenty of other shocking moments in this episode, most notably that final showdown between Tywin and Tyrion.
Benioff and Weiss are more than justified to make whatever artistic decisions they want, but the problem, of course, is the internet. The second the Lady Stoneheart reveal doesn't happen, all the book fans start freaking out, and word leaks out enough that the ultimate reveal will probably be less effective. Again, I don't think that Benioff and Weiss should be deciding how to write their show based on internet fandom, and they would probably argue that the vast majority of Thrones' huge audience will remain unaware of any omitted scenes.
It also plays into how the show has been written thus far. Usually, the big epic plot twists are deployed in each season's penultimate episode—Ned being beheaded in season one, Stannis' defeat at the Blackwater in season two, the Red Wedding in season three. The final episode is usually a little quieter and serves to set up the next season. But these finales are not without their shocking conclusions: the birth of the dragons in season one, the march of the White Walkers in season two. But season three finished with Daenerys' liberation of Yunkai, a visually sweeping but somewhat foreboding moment, pointing vaguely to future plot without doing anything too shocking. Ending with Arya's journey echoes that approach, and given the focus on the trials and tribulations of the scattered Stark children this season, it may have been the right call.