The Lord of the Rings Explained – Reinforcements at Helm’s Deep

Reinforcements do arrive in the book, but they arrive much later than in the film, they’re not elves, and Haldir has nothing to do with it.  And the scene from the movie where Haldir dies in Aragorn’s arms?  That also never happened.

Huorns

After the Entmoot, as the Ents were marching to Isengard, Pippin looked behind them and see that what had previously been bare slopes were now covered with trees.  What’s more, the trees were moving.  They’re called “Huorns” and we learn later on that they were probably ents that have gradually become more like trees.

Huorns are described as being able to wrap themselves in shadow and move quickly when angry.  They can still communicate with Ents, despite their treeishness.  It’s hard to see them move if you’re looking at them, but the moment you look away, they’ll be all around you.

That last part was probably partly inspired by a plot point in Shakespeare’s Macbeth, where Great Birnam Wood is prophesied to march on King Macbeth and then… doesn’t.  What actually happens is this: Macbeth’s enemies sneak up on him using branches to disguise themselves as trees.

Tolkien found the fake-out in Macbeth rather disappointing.  This lead to his writing a plot point in his book where the forest really does march on Saruman.

Keep Away From the Trees!

No matter what you might think of Shakespeare, when King Théoden and his men rode out from Helm’s Gate, they saw that there was now a forest of trees in the Deeping coomb where none had grown the evening before.  That’s right; it’s the trees—not the elves—that come to the Rohirrim’s aid at Helm’s Deep.

With the timely arrival of Gandalf and Éomer’s riders, the terrified orcs fled into the forest of Huorns and were never seen or heard from again.

With the timely arrival of Gandalf and Éomer’s riders, the terrified orcs fled into the forest of Huorns and were never seen or heard from again.