The Nights Sword

Official quest description: Sir Vyvin's squire is in trouble. He has accidentally lost Sir Vyvin's ceremonial sword. Help him find a replacement without Sir Vyvin finding out.
Release date: 6th April 2001
Start: Talk to the squire located in the White Knights' Castle in Falador.
Difficulty: *****
Length: Medium
Members only: No
Requirements:
10 Mining
Ability to evade level 57 Ice Warriors and level 53 Ice Giants
15 Smithing to smelt two irons bars and 10 Cooking to cook a redberry pie. (Helpful, but not required)
Items needed:
Redberry pie
A pickaxe
2 iron bars (4 if you want your own blurite sword)
1 blurite ore (2 if you want your own blurite sword).
Monsters to kill: None
Spoiler warning: Plot and/or ending details follow.
edit Walkthrough

This is where you start The Knights Sword.
For convenience's sake, it is advised for players to get the necessary items before starting the quest. This means getting 2 iron bars (4 if you want your own copy of the blurite sword) and a redberry pie. Players may either make these themselves, which requires 15 Mining and Smithing for the bars, and a pickaxe, and 10 Cooking for the pie. Alternatively, players may simply buy them at the Grand Exchange.
The squire in Falador will tell you he lost Sir Vyvin's sword, and would like you to help him replace it. The squire will tell you to talk to Reldo, Varrock's librarian. Go to Varrock Castle and to go the far north of the castle to find Reldo.
Ask Reldo about Imcando dwarves. Reldo will tell you that one is located on the souther peninsula ofAsgarnia. If you haven't already made a redberry pie, make one now. If you have, continue to Asgarnia and then head south.
You should see a small house on the side of a hill with an anvil logo. Look for Thurgo, the Imcando dwarf. Ask him if he would like some redberry pie, an offer he'll readily accept. Talk to him again, and ask him about the sword. He says he'll need a picture of it. Go back to Falador and talk to the squire again.
The squire will tell you that Sir Vyvin has a portrait of the sword in his room. Go to the third floor of the castle and find Sir Vyvin (his room can only be accessed from the second floor, up the stairs in the middle of the castle). Look for a cupboard nearby and open it and search it. You will obtain a portrait that shows the sword. However, Sir Vyvin will stop you if he is in the room. There are three ways to avoid this:
Have a friend talk to Sir Vyvin while you open and search the cupboard.
Open the door to his room and wait for him to walk out. However, this will take a very long time. Just shut the door when he leaves and then search the cupboard.
Have the door open, and wait next to the cupboard. When Sir Vyvin walks behind the door, quickly search the cupboard.
Once you have the portrait, go back to Thurgo.
Talk to Thurgo and give him the portrait. He will tell you that the sword he is making is a blurite sword, however he will need the materials to make the sword. You will have to enter the dungeon on the hill nearby to obtain the blurite ore, with your trusty pickaxe, of course. All enemies in the cave are aggressive so bringing food and armour is a good idea. When you see white ahead of you, be prepared to run along the walls to find the blurite rocks, which are grey with bright blue streaks running down the sides. Mine one or two blurite ore depending on whether or not you wish to create a sword for yourself. When you have the amount of blurite you want, run out.
It may be helpful to have a bodyguard to protect you from the aggressive monsters; however, if done correctly, a level 3 player can get the ore.
Note that the spot right next to the entrance to the members-only area of this dungeon where the Skeletal Wyverns are is a safe spot. It is recommended you mine the blurite ore rock right next to this area, so you can easily retreat to safety if necessary.
The blurite rocks now have the "seam rock" style with only a vein of colour, instead of their old solid colour style and the positions have changed from those shown in many guides.
Talk to Thurgo with your blurite ores and your iron bars. He will make you a sword. To make more swords for yourself, drop the sword Thurgo just made and talk to him again with the materials. He will the make you a second sword. Pick up the sword you dropped. If players want to, they can continue repeating this to obtain as many swords as they like.
Go back to the squire and talk to him. If you talk to him while holding two or more swords, he will take both of them, so it is recommended that you bank one or drop it before you talk to him, then pick it up after. You will be done with the quest when you've given him the sword. Note that if you lose these swords, there is absolutely no way to get them back.