Though "The Watchers on the Wall" ended at a similar place as it began — with the Night's Watch weak and a mass of wildlings approaching — there's plenty to dig into about the raid on Castle Black that the show merely touched upon. Here's a a non-spoilery book reader's explanation of Ygritte and that cave, that woolly mammoth-riding giant, and Tormund Giantsbane's sexual prowess over bears.
Ygritte and the cave
Ygritte's death isn't quite as dramatically timed in the books — Jon simply finds her with an arrow in her — but her last words hit the same depressing notes as Jon Snow holds her.
"D'you remember that cave? We should have stayed in that cave. I told you so."
"We'll go back to the cave," he said. "You're not going to die, Ygritte. You're not."
"Oh." Ygritte cupped his cheek with her hand. "You know nothing, Jon Snow," she sighed, dying.
So, do you remember that cave? Jon and Ygritte certainly do, especially because Jon brought out his "Lord's Kiss" move on Ygritte, essentially inventing third base as far as Westeros is concerned. Let's flash back to an earlier part of the third book. "I don't ever want t' leave this cave, Jon Snow. Not ever," Ygritte says. Dammit Jon, why didn't you listen to the woman! Oh George R.R. Martin, you devil you, why do you have to always ruin true love?
Mag the Mighty
That woolly mammoth-riding giant who lifted the Wall's gate wasn't just some random huge giant, he is Mag the Mighty, the most famed warrior of the Giants. When Jon Snow goes undercover with the wildlings, Jon gawks at the massive Mag and gains some respect for him and his kind. Giants used to be everywhere in the ancient history of Westeros, but they have been hunted to near extinction by smarter humans. As Time's James Poniewozik notes, the show has largely painted all wildlings as evil raiders, whereas in the books there is some sympathy for their position on the wrong side of the Wall. The end of the giants, in particular, are a somber story.
That means that when Jon goes down below into the tunnel to find Mag dead alongside several Night's Watch brothers, he feels sorrow for both parties. Jon "could feel the sadness there, but he had no time for sadness," he notes after looking at a dead Mag. Spill some hot mulled mead for all my dead giants out there.
Janos Slynt's past at King's Landing
The Night's Watch is full of former criminals and lackeys, and that's never more obvious than in Janos Slynt, the bald and scared Night's Watchman who hates Jon. "I commanded the City Watch of King's Landing. Those men obeyed orders," Slynt says longingly. Indeed, they definitely obeyed his orders back in season one, when as commander he turned on Ned Stark during his attempted coup, all under the scheming of Littlefinger.
In season two, Tyrion Lannister becomes the Hand of the King and immediately sends Slynt away to the Wall for being a skeezeball who could be bought. That was good for Tyrion but bad news for Jon, who's had to deal with the jowly jerkface ever since. Janos Slynt is the worst, so of course he survives the battle.
Tormund Giantsbane, Husband to Bears
When the red-bearded Tormund starts to tell a campfire story about his crazy night with a beast named "Sheila," Ygritte interrupts. "I know you never fucked a bear. You know you never fucked a bear. Right now, I don't wanna think about the bear you never fucked," she says. Yes, Tormund often tells the same story about his relations with a bear, and even fashions himself "Husband to Bears" in the books. At one point, Tormund tells Jon the whole story of his supposed sexual prowess.
"I was in me Ruddy Hall, with only a cask o’ mead to keep me company and nothing to do but drink it. The more I drank, the more I got thinking about this woman lived close by, a fine strong woman with the biggest pair of teats you ever saw. She had a temper on her that one, but oh, she could we warm too, and in the deep of winter a man needs his warmth.
"The more I drank, the more I thought about her, and the more I thought the harder me member got, till I couldn’t suffer it no more. Fool that I was, I bundled meself up in furs from head to heels, wrapped a winding wool around me face, and set off to find her. The snow was coming down so hard I got turned around once or twice, and the wind blew right through me and froze me bones, but finally I come on her, all bundled up like I was.
"The woman had a terrible temper, and she put up quite the fight when I laid hands on her. It was all I could do to carry her home and get her out o’ them furs, but when I did, oh, she was hotter than even I remembered, and we had a fine old time, and then I went to sleep. Next morning when I woke the snow had stopped and the sun was shining, but I was in no fit state to enjoy it. All ripped and torn I was, and had me member bit right off, and there on me floor was a she-bear’s pelt. And soon enough the free folk were telling tales of this bald bear seen in the woods, with the queerest pair o’ cubs behind her. Har!" He slapped his meaty thigh. "Would that I could find her again. She was fine to lay with, that bear. Never was a woman give me such a fight, nor such strong sons neither."
So there you go: Tormund Giantsbane, Husband of Bears, got incredibly drunk and horny and so mistakenly skinned and then raped a bear. Coolest of stories, bro, and one he'll have plenty of time to tell in his time as a POW at Castle Black.