Arya now has a Valyrian steel weapon, but where did it come from?

Spoilers for Game of Thrones Season 7, episode four follow. Don't act like you haven't been warned. That would embarrass everyone.

Well, that wonderful episode gave us many, many things, but it also gave Arya a Valyrian steel dagger.

Littlefinger, in his smarmy way, tried to bond with the newly-returned, newly-creepy Bran by giving him a very special dagger. Bran saw right through the twerp's greasy smile ("Chaos is a ladder."), but had no real need of the knife. So, he gave it to Arya in the midst of that very touching Stark family underneath the red leaves of the weirwood tree.

But where did it come from and what does it mean?

The dagger made its first appearance waaaaaaayyyyy back in the second-ever episode of this long-running show. You'll remember in the first episode, an adventurous and much younger Bran unadvisedly climbed up into a Winterfell window and spied Lannister siblings Jaime and Cersei engaged in sexual congress, and he paid for it by being pushed out of a window by Jaime "Kingslayer" Lannister.

He fell into his ongoing paralysis and a coma. During this convalescence, a paid assassin started a fire in Winterfell, trying to draw people away from Bran's room. And so, the would-be killer entered the room, equipped with the dragon bone-hilted, Valyrian steel dagger and finds only Bran and his mother Catelyn Stark.

Catelyn puts up a valiant and bloody fight, but in the end, it is Bran's adopted dire wolf, Summer, who saves the comatose boy from the Valyrian blade.

The blade proves quite a plot point, as Catelyn uses it to determine who, exactly paid an assassin and equipped them with such a valuable weapon to murder her son. On the way to King's Landing, when her husband Ned was still alive and the Hand of King Robert Baratheon, Catelyn shows the dagger to Littlefinger, who says it belonged to Tyrion Lannister.

Well.

This is what kicks up the whole Lannister v. Stark feud, as Catelyn imprisons Tyrion for trying to kill her son. That led to his being held in the Eyrie where Bronn had to prove Tyrion's innocence by defeating the Lady Lysa Arryn's champion

The dagger is last seen on Ned's desk in King's Landing. After Littlefinger betrays him to his death, the schemer takes it back. Only to give it to Bran, who gives it to Arya.

But who paid for Bran's assassination in the first place?

That is something that is very much still up for debate. Most of the evidence in the show and the books points to unfortunate purple wedding-attendee King Joffrey being the one who paid for the assassination to impress King Baratheon. Though many still believe that Littlefinger himself was responsible for the attempt.

Regardless, this episode gave another Stark a very, very rare Valyrian steel weapon. It has long been theorized that these scattered relics will prove decisive in the coming white walker battle. This seems especially true since, Jon Snow now has access to a whole mine of dragon glass, which is supposed to be the key ingredient to making Valyrian steel.

Either way, we think that this Valyrian steel weapon wound up in the right hands.