The clip Saruman's army from The Lord of the Rings: The Two Towers (2002) with Christopher Lee, Brad Dourif
Its outer wall is solid rock but for a small culvert at its base which is little more than a drain.
How? How can fire undo stone?
What kind of device could bring down the wall?
If the wall is breached, Helm's Deep will fall.
Even if it is breached, it would take a number beyond reckoning thousands, to storm the Keep.
Tens of thousands.
But, my lord, there is no such force.
A new power is rising.
Its victory is at hand.
This night the land will be stained with the blood of Rohan!
March to Helm's Deep!
Leave none alive!
There will be no dawn for Men.