The Door is one of the most gut wrenching episodes and battles in Game of Thrones because it did not involve an army or an armada. Instead, it established the origins of the Night King and delved into the Children of the Forest’s role in his creation. It was also one of the most heartbreaking battles because of the deaths of well loved characters like Summer and Hodor. I was an emotional wreck when I first watched it and was even more so after I rewatched it, even knowing what would eventually happen.
The Door was a heart pounding battle mainly because it challenged the safety of Weirwood Tree, the home of the Three Eyed Raven as well as the protection that the Children of the Forest can offer Bran, who was being trained to take the place of the greenseer who can see the past, present and the future.

Despite being outnumbered, the Children of the Forest, along with Meera and Bran warged as Hodor, did put up a pretty good fight. But the sheer number of the White Walkers overwhelmed them. This battle, which happened at the Weirwood Tree, had different facets as Bran shifts from his dreams to reality. He comes face to face with The Night King for the first time and also feels an uncanny connection with him like Jon Snow. It actually dawned on me as I rewatched this episode that perhaps, the Night King is connected to the Stark bloodline as perhaps, the First Man could have been a direct ancestor of Lords of Winterfell. Its not completely impossible because it can be assumed that the Night King was a Northerner as they were closest to the home of the Children of the Forest. This is just me gabbing.
The Door was an intense battle because there was very little room to escape, in contrast to the number of the White Walkers that were attacking. It was a literal zombie swarm with very little hope for survival.
It was also very tragic because my beloved Summer (I love these direwolves), in an attempt to save his master, sacrificed his life in battle. Leaf also commits the ultimate sacrifice to give Bran, Meera and Hodor the opening they need to escape the Weirwood Tree. In the final moments, the ultimate twist is revealed about how Hodor came to be and this was a very cruel but brilliant move on the part of showrunners.
Bran watches in his vision as the once a normal boy named Wylis, is attacked by a seizure in Winterfell as he yells “Hold the Door.” It turns out that this was Meera’s final command to Bran’s loyal servant so she can save Bran once and for all. Hold the Door eventually morphs into Hodor, the only word Willis can say from that day on.
After all these sacrifices, it further solidifies the theory that Bran will play an important role in the Great War to come. He must. He just must or Game of Thrones simply enjoys breaking our hearts in graphic ways. RIP, Summer, Hodor, Three Eyed Raven and Children of the Forest.