The Silver Hand

Two things to summarize for modern completion of this quest (thanks to the others in this thread):
1) Don't kill the giant aberration too fast, before Travard can engage it. If you do, use your portal scroll rather than leaving instance to save yourself one load screen. Either way, you'll need to start over.
2) When you get to the part where you need to cleanse two Righteous Crusaders, switch to Holy. Prot doesn't get the ability to cleanse magic.

I don't know if anyone else is having problems with where the quest turn-in marker is on the map, but ...
Despite the quest turn-in marker being in Dalaran, it's correctly in the Sanctum of Light.
Return to your Order Hall, and Tyrosus is there waiting for the turn-in.

Video Guide: https://www.youtube.com/watch?v=gy0AYLFRI8A

1. The Silver Hand (Scenario)
• Accept the quest, The Silver Hand, from Travard at coords 72.2, 49.0 (Krasus' Landing in [zone=7502]).
• Head to the center of [zone=7502], and step on the transporter at 49.1, 47.8.
• Go southwest, down the corridor and steps to 29, 76.
• Click the Portal to Dalaran Crater.
• Travel northwest, into [zone=8044], to Tyr's Fall at coords 13, 57.

Stage 1 - The Empty Camp
• Speak with [npc=106429].

Stage 2 - Clearing the Way
• Inform [npc=106429] when you are ready, and then follow him underwater, in the lake, to coords 37.5, 13.1.
• Swim through the underwater passage to the Vestibule of the Silver Hand at coords 35, 32.
• Heal your group while it battles the [npc=106579].

Stage 3 - Keeper's Rest
• Enter the Tomb of Tyr with your group, and speak with [npc=106429] when you are ready to proceed.
• While your group fights the mobs, stand close to [npc=106429] (Tank) as he will pull mobs off of you, if you receive aggro.
• After the room is cleared of the [npc=106579], [npc=106624] will appear for your group to fight.
- - When possible, try to stand near the back of [npc=106624], to avoid damage from [spell=215705].

Stage 4 - The Broken Ritual
• Listen to [npc=106639], who informs you that part of the supplies needed to complete the ritual is located below.

Stage 5 - Into the Dark
• Speak with [npc=106639], when you are ready to proceed below.
• Follow your group through the Darkwalk where you will encounter the first pack of mobs, [npc=106578].
• In the next room, at coords 42, 84, your party will battle more [npc=106579].
• Follow your party northeast to a barrier at 47.6, 75.5.
• When the barrier goes down, stay with [npc=106639] as he fights more [npc=106578].

Stage 6 - The Maw of the Beast
• Speak with [npc=106676] when you are ready to proceed, and then follow the party across the bridge to 58, 75, where you will engage [npc=106669].
- - Where possible, stand behind [npc=106669] to avoid damage from [spell=215797].
• Shortly before its death, the [npc=106669] kills [npc=106370] and [npc=106371], leaving [npc=106676] all that remains of your party.

Stage 7 - Escaping the Prison
• Follow [npc=106676] southwest, back to coords 43, 82.

Stage 8 - Aid to the Fallen
• While [npc=106676] holds off Mordoth the Hunter, heal the [npc=106721] and [npc=106722].
• Use [spell=4987] on the pair of [npc=106933].

Stage 9 - Something is Coming
• Follow [npc=106676] north, back to the Tomb of Tyr at 37.5, 63.4

Stage 10 - Ritual Defense
• Heal your damage dealers while [npc=106677] completes the ritual.
• Stay close to [npc=106774], as he is now your group's tank.
• At approximately 50% of your ritual status bar, Mordoth the Hunter will come up from the tunnel.

Stage 11 - The Silver Hand (Final Stage)
• Once the ritual bar is filled to 100%, Mordoth the Hunter will break combat.
• Collect [object=249824] at 37.3, 54.7, to claim your artifact weapon.
• After collecting the weapon, the cut-scene will show you exit the Tomb, and the collapse of the Tomb.
• After appearing on the surface, follow [npc=106677] to 13.0, 57.4, and click on the [npc=106421] to take you back to [zone=7502].
• After landing in [zone=7502], turn in the quest to [npc=106834].
- - If you have already completed a different artifact chain, [npc=90259] will be located at 49.6, 71.5 in the [zone=7638].

** IMPORTANT NOTE: [spell=4987] may NOT work on the [npc=106933] unless you're in HOLY spec. **