Multiple reasons:
Escape the white walkers, Gain freedom, Take over the wall. Not sure if they'll get to the climax in this season, but it is unforeseeable and amazing.

If i remember correctly they are climbing over the wall to one of the many castles along the wall. Most of them have been deserted due to the fact that there aren't many men on the nights watch anymore. From there they are going to get more people over the wall then do a surprise attack on castle black so that all the wildlings are able to get through.

It's something along those lines, but it's been a while since i've read the books.

They are climbing the wall to make an attack on Castle Black from the south while Mance Rayder sieges the wall from the north. The gate isn't impenetrable. However, Mance can't sustain the hurt that could be put out from on top of the wall while trying to break through, so he needs the brothers of the Night's Watch to be distracted fighting an enemy on the wrong side of the wall.

People forget that "Castle Black" is a castle only in name, just like the rest of the keeps built along the wall. They have no defense from an attack coming from the south.

What are they hoping to accomplish from this assault? If they simply wanted to cross the wall and move on, there would seem to be much safer ways of doing it. Did I miss some backstory that explained why the wildlings hate the Nightswatch so much?

Life North of the Wall sucks.

It's cold 90% of the time, there isn't any tillable land, there are Dire Wolves and Giants and a thousand other nightmares. Oh yea, and the White Walkers have come back, and have been slaughtering the population and raising them as zombies.

On the other side of the wall there is a lot of tillable land, and they could be on the other side of a giant fucking wall of ice from all the beforementioned problems.

When the Wall went up the Night's Watch said "If you are on our side, you are a good guy. If you're on the other side, you're a bad guy, and trying to destroy the realm, and thus are Bad."

The whole thing is an allegory for Hadrian's Wall where the Romans built a wall to keep the Scots out, who they deemed as rapers, pillagers and general Gentlemen of Ill Repute. This meant that all the Scots north of the wall had to engage in vicious eternal battle with their most hated of enemies, the Scots.

it's not about them hating the night's watch it's just about getting through the wall easily, they can't have their whole horde climbing it. i guess straight through castle black is the easiest?

and wow i just remembered coldhands, he should be coming up soon, will be great to see what he looks like.

Castle Black has the long tunnel through the Wall, which is why it is the Night's Watch main base.

There's honestly a whole lot of story North of the Wall that's been skipped over, removed, or not alluded to. Mance is a lot less sympathetic (and interesting) character in the TV series than the books. They skipped out the story why he left the Night's Watch, his wife, the fact he was a singer and many other details.

Every keep along the wall has a tunnel, it's just that the only ones not abandoned and filled with ice are Castle Black, Eastwatch by the Sea and The Shadow Tower.

Also, Asano, they're running for their lives. The white walkers are no joke.

Ahh, thanks for the clarification all. I figured there was a ton of backstory that we just don't get on the show. One of the drawbacks of trying to condense such an immense story into 10 episodes per season, I guess.

We've only seen small bits of the white walkers so far, and while I get that they're not terribly friendly creatures, the show really hasn't shown us what a big threat they really are. Certainly not a big enough threat to send all of the wildlings fleeing south. I assume we'll be seeing much more of them later.

Didn't know the tunnels at the other castles were filled with ice. That makes a lot more sense now too.

The simple fact is too, no one in westeros really knows anything about the wildlings. They just know they don't want them around. In reality, they are just people trying to carve out a life in a terrible environment with terrible things like the white walkers out there. Like Quinn said, some stuff has been skipped over, like Mance knows who jon snow is because he regularly crosses the wall and would do things like sneak in to their parties and pose as a singer.

I dont understand why geoffrey killed that prostitute

Because he's fucked in the head.

Baelish help set that up as well so i imagine he was selling it to the king in order to facilitate many angles that he has. Did that happen in the books?

No, it didn't

Roz was a character who was a minor mention in Book 1 whom they expanded on greatly. So, her death was a representation of someone who tried to climb the ladder, and failed. It was invented for the show.

Joffrey's just a sociopath, who became that way raised in power and wanting for nothing, and no one ever telling him no. The inbreeding doesn't help.

A couple of episodes ago when jeoffrey-goffrey-geoffrey**** took his shirt off they didnt even air brush ABS on the dude!!! and he clearly didnt take his 300 workout serious.. MIRT

URT, and it's Joffrey.

Does jeoffery even lift, bro?

someone get tonights episode up ! I wont be home tonight to see it

How the fuck did those guys carry two cases of gold bars so easily? Those cases had to weigh over 300 pounds each.

edit: cold = gold :D

haha, i thought the same goddamn thing. Also, Jeoffery sitting in that room alone. Cracked up.

http://oyster.ignimgs.com/mediawiki/...ite_Walker.jpg

Blake at the age of 40 if he keeps doing so many drugs.

That's cold.

I think we're ALL wondering why Daario's hair wasn't blue AND he didn't have the awesome beard. LAME!

I think I get the lack of blue, I think people would have just laughed, but he definitely could have a beard. But he had naked chick weapons atleast! He's a kind of weird looking guy.

I was just being gay, but yea.

No episode next week. Sorrow.

Then, well.

Yea.

http://www.youtube.com/watch?v=2l7wzOaODYQ

(Don't read any comments on that video).

I know, the week off blows.

Tonight, Gentlemen.

Tonight.

You've been hyping it up quite a bit the last few weeks. I hope it delivers.

So good

I knew what was coming and I was still like "fuuuuuuuuuuuuuuuck"

Right in the baby maker!

That was a crazy episode.

Holy shit omfg holy shit wtf holy shit wow

Insane. Definitely delivered.

yea pretty crazy ep

/swoon, so awesome.
They did a good job of cramming all that into one episode.

I am pretty sure George R Martin is a demon who is powered by tears.