You might think that, between divided loyalties and family betrayals, parentage reveals and Jon Snow rising from the dead — not to mention religious fanatics, blood magic, shadow-babies and warging — Game of Thrones couldn't actually get any more complicated.
Having now watched Season 6 Episode 5, "The Door," an episode packed to the brim with significant plot developments, you'll know that you were very much mistaken, because after tonight there's an extra facet to this show that could complicate the question of who'll reside on the Iron Throne when the war is over: time travel.
Major spoilers ahead for Episode 5 and the remainder of Season 6.
The Tragedy Of Hodor
Until tonight's episode, I thought I wanted to know exactly how Wylis became Hodor. Turns out ignorance was bliss.
One of the more subtle elements that made this episode of Thrones so great was the fact that lines of dialogue spoken by characters outside of Bran's story echoed back in a way that made them relevant to Hodor.
Both Sansa's reminder that Littlefinger was supposed to be her protector and Jaqen's assertion that "a servant does not ask questions" both concisely summed up Hodor's role in Bran Stark's life. In a way, Hodor lived his life as the ultimate servant, no questions asked, always there when called upon.
But how exactly did Meera's words in the present turn Wylis into Hodor in the past? It may seem complicated, but as a concept it's actually quite simple.
A Matter Of Time
In essence, writers Benioff and Weiss plotted this Hodor reveal in a way that commits Game of Thrones to the idea of time as a causal loop.
What this means is that events in the present can be engineered by events in the future, or that things happening in the present (for instance, Bran warging into Wylis inside the Raven's vision) can be directly responsible for something that happened in the past (Wylis having the fit that left him screaming out that command and consigned him to life as Hodor).
The beginning of the loop is impossible to determine — it just exists — which differentiates the causal loop theory from other time travel theories such as that used in The Flash, which takes the view that time can be rewritten and one timeline superseded by another. Bran doesn't consider that warging into Wylis could be problematic, having previously warged into adult Hodor, unaware that the causal loop would be responsible for turning Wylis into Hodor.
The Hodor reveal was also the rare occasion in which Thrones both stunned and saddened at the same time (as opposed to making me sad for Shireen's death, which we all knew was coming, or shocking with the death of Balon Greyjoy, about whom I didn't care).
It was so effective because Hodor had, up until this point, been kind of a joke figure. A little comic relief in the midst of a very dark saga. He only says Hodor! Ha, ha! The truth is the joke was on us, because Hodor died a hero, almost an entire lifetime lived with the sole purpose of being in the right place at the right time to hold a door so that somebody deemed more important by virtue of his bloodline could live.
The question now becomes whether Bran, without the guidance of the Raven to fall back on, will continue to set events into motion in the present that become responsible for events in the past, beginning with the Tower of Joy. Did Ned really hear his son call out, or was he distracted by something else?