Those of you who watched last night's episode of Game of Thrones might be wondering what the heck was going on in Bran's flashback scene. What was that place? Who were those people? Is this actually important? If you're still clueless about the whole thing, allow me to clear things up.
WARNING! Spoilers from last night's episode (and possibly the books) follow!
As we've seen this season, Bran Stark is using his magical powers to interface (so to speak) with Westeros's weirwood trees and see what's happened in the past as if he were actually there the first time round. Last night's flashback takes place right at the end of Robert Baratheon's rebellion against Aerys Targaryen (aka The Mad king, father to Daenerys) at The Tower of Joy in Dorne.
The tower is significant, because it's housing Lyanna Stark, Ned's younger sister and the reason Robert rebelled in the first place.
The story has a few pieces, so bear with me. Long before the rebellion was even a thought in the back of someone's head, Robert and Lyanna were betrothed and set to be married. The problem was that Lyanna also caught the eye of someone else, Rheagar Targeryan (heir to the Iron Throne and eldest brother of Daenerys).
After winning the tournament at Harrenhall, tradition dictated that Rhaegar was to declare a single woman in attendance as 'the goddess of love and beauty' by presenting them a blue rose. Everyone assumed that he would choose his wife, Elia Martell of Dorne, but instead he scandalously presented the flower to Lyanna. That's the kind of thing that would send Westerosian Heat Magazine into an utter frenzy.
A year later, as the story goes, Rhaegar kidnapped Lyanna and kicked off a chain of events that led to Robert and Ned openly rebelling against the Targeryan dynasty. They were eventually successful, having won over much of the realm in the process. Robert killed Rhaegar at the Battle of the Trident, the Lannisters successfully ransacked Kings Landing, and Jaime Lannister broke his oath to the Kingsguard by assassinating the Mad King. The only thing left to do was recover Lyanna, so Ned gathered a few loyal bannermen and headed to the Tower of Joy to do just that.
Last night's Game of Thrones covers what happens next. The tower is guarded by members of the Kingsguard, and after a fight the only two people left standing are Ned Stark and Howland Reed (father to Bran's companions Meera and Jojen). This leads us to one of the more popular and convincing theories about what's to come in George RR Martin's saga.
Why was Lyanna being protected by the Kingsguard, rather than regular Targeryan soldiers? The theory is that it's because Lyanna was pregnant with Rhaegar's child, a child that would later become known as Jon Snow. Shocking, right? But it kind of makes sense that the Kingsguard would be tasked with protecting the woman pregnant with the child of the heir to the throne, bastard or not. Rhaegar's child could make a claim to the Iron Throne if (and only if) the rest of the Targeryans died.
The problem is that the show is being very stingy with the resolution, as are the books. Nobody knows for sure what Ned will find inside the Tower, other than the fact Lyanna lies dying on a "bed of blood" surrounded by blue roses. Before dying Lyanna made Ned promise her something, but we don't know what exactly. If the Jon Snow thing is true, it's more than possible that she made Ned swear to protect and raise her child.
Ned Stark, being the honour-crazy man that would eventually lead to his death, would likely take on Jon as his own bastard - to conceal the truth about his true parentage from the rest of the world. The only person who would know otherwise is Howland Reed. Doing so would sacrifice Ned's own honour in order to protect Lyanna's, because whether or not she willingly left with Rhaegar the idea of a high born woman having a child outside of marriage was a serious scandal. This is a medieval world, after all.
It also makes more sense than the current knowledge, because why would honour-obsessed Ned Stark willingly sleep with a woman while already married? It also protected Jon from Robert, who we've already seen was more than willing to kill any potential Targeryan usurpers.
So what the heck does this mean?
For starters it means that there could well be a second Targeryan to pinch the Iron Throne back from the Lannisters. It also lends credence to Melisandre's claims that Jon is the 'Prince That Was Promised', and defend the world from the ever-encroaching White Walkers. It's a lot easier to be a prince when you have royal blood, after all.
We're going to have to wait and see, though. Whether or not we get any definitive answers this season has yet to be seen, but it should be interesting to find out.