Simultaneously with this explosion, crowds of orcs begin to besiege the gates. In the book, it is not explicitly clear how the orcs blast a hole in Deeping Wall, since Aragorn vaguely refers to it as “some devilry of Orthanc” (Tolkein 669). Also in the book, the gates are the first to be attacked, and when this happens Aragorn and Eomer leave the Deeping Wall:
“Come!” said Aragorn. “This is the hour when we draw swords together!” Running like fire, they sped along the wall, and up the steps, and passed into the outer court upon the Rock. … There was a small postern-door that opened in an angle of the burg-wall on the west, where the cliff stretched out to meet it. On that side a narrow path ran round towards the great gate, between the wall and the sheer brink of the Rock. Together Eomer and Aragorn sprang through the door, their men close behind. The swords flashed from the sheath at one (Tolkien 662-663).
Gimli is present in this part of the book too, saving Eomer just as two orcs are about to attack him. In the film, there is some “over-the-top” moments during this segment of the battle, particularly Legolas sliding down the stairs of the Deeping Wall on a