[THEORY] What do the spells in the Barrow-blades DO? Burn.
# PREFACE:
Okay, now everyone has their opinion on whether or not the Barrow-blades had a 'bonus' effect on Nazgul. Here is the commonly debated passage:
>"So passed the sword of the Barrow-downs, work of Westernesse. But glad would he have been to know its fate who wrought it slowly long ago in the North-kingdom when the Dúnedain were young, and chief among their foes was the dread realm of Angmar and its sorcerer king. **No other blade, not though mightier hands had wielded it, would have dealt that foe a wound so bitter, cleaving the undead flesh, breaking the spell that knit his unseen sinews to his will.**"
I'm firmly in the camp that *"broke the spell that knit the sinews to his will"* is merely stating the Witch-king was rendered unable to move - and drops to his knees in sheer pain (as anyone would when being stabbed in the leg). His body could not do as his mind desired in this moment of pain - the 'spell' between body (sinews) and will (mind) was severed temporarily.
Alternatively, some read 'spell that knit' as more magical, and that somehow the blade broke the Witch-king's hold over his own material body.
I don't want to dwell much on this topic, but **my theory will be under the assumption that the Barrow-blade ONLY caused the Witch-king PAIN, and left him in SHOCK**.
>**"But suddenly \[the** **Witch-king****\] stumbled forward with a cry of bitter pain**.... Merry's sword had stabbed him from behind, shearing through the black mantle, and passing up beneath the hauberk had pierced the sinew behind his mighty knee."
*So what did these spells actually do, if not 'make the Witch-king mortal', as many like to believe?*
# WHY COULD THE BARROW-BLADES CAUSE MORE PAIN THAN ANY OTHER BLADE COULD?
Now, one way or another, these blades DID contain spells:
>"Doubtless the Orcs despoiled them, but feared to keep the knives, knowing them for what they are: work of Westernesse, wound about with spells for the bane of Mordor."
Tolkien uses *a lot* of **FIRE SYMBOLISM** when speaking about the Barrow-blades. Let's go over a few quotes:
>"For each of the hobbits he chose a dagger, long, leaf-shaped, and keen, of marvellous workmanship, **damasked with serpent-forms in red and gold**. They gleamed as he drew them from their black sheaths, wrought of some strange metal, light and strong, and **set with many fiery stones**. Whether by some virtue in these sheaths or because of the spell that lay on the mound, the blades seemed untouched by time, unrusted, sharp, **glittering in the sun.**" > >... > >"Desperate, \[Frodo\] drew his own sword, and it seemed to him that it **flickered red, as if it was a firebrand.**" > >... > >"\[Pippin\] drew his sword and looked at it, and the intertwining shapes of red and gold; and the **flowing characters of** **Númenor** **glinted like fire upon the blade**. 'This was made for just such an hour,' he thought." > >... > >"Then \[Merry\] looked for his sword that he had let fall; for even as he struck his blow his arm was numbed, and now he could only use his left hand. And behold! there lay his weapon, **but the blade was smoking like a dry branch that has been thrust in a fire; and as he watched it, it writhed and withered and was consumed.**"
Of less relevance, but interesting regardless (very poetic)... the blades are a type of **antithesis** to the Barrow-wights - who surprise surprise... represent the **COLD**:
>"He \[Frodo\] was suddenly aware that it was getting **very cold, and that up here a wind was beginning to blow, an icy wind.** A change was coming in the weather. The mist was flowing past him now in shreds and tatters. His breath was smoking, and the darkness was less near and thick." > >... > >"Trembling he looked up, in time to see a tall dark figure like a shadow against the stars. It leaned over him. **He thought there were two eyes, very cold** though lit with a pale light that seemed to come from some remote distance. **Then a grip stronger and colder than iron seized him. The icy touch froze his bones**, and he remembered no more."
And later:
>"Then at last \[Sam\] began to weep; and going to Frodo he composed his body, **and folded his cold hands upon his breast**, and wrapped his cloak about him; **and he laid his own** **sword** **at one side**, and the staff that Faramir had given at the other.
> >'If I'm to go on,' he said, 'then I must take \[Sting\], by your leave, Mr. Frodo, but I'll put this one to lie by you, as it lay by the old king in the barrow...."
Frodo is *cold*, and Sam lays his Barrow-blade beside Frodo - almost symbolically *warming* him.
# CONCLUSION:
Anyway, I propose that upon being stabbed, the Witch-king not only felt the *stab* of the blade, by was also **BURNED** by the spells imbedded in the blade. Burning sensations are *notoriously* painful.
This would explain why:
>**"No other blade, not though mightier hands had wielded it, would have dealt that foe a wound so bitter"**
Standard blades do not burn foes on top of other physical wounds. Barrow-blades are special in this regard. The Uruks were right to throw away these blades in fear.