Video Guide: https://www.youtube.com/watch?v=q5OADIwwy_I
Pick up the quest from [npc=83549] at coords 59.7, 60.8 (in front of Stockton Brewery) -- If you have chosen Smuggler's Inn for your building, you will not be able to complete this chain.
1. Attempted Murder - (Video) - Talk to [npc=83567] at coords 39.0, 61.8, your Flight Master and select "Take me to Shadow's Vigil."
• You will be flown to Shadow's Vigil. Turn in this quest, and pick up the next from [npc=83609] at coords 52.1, 23.5 (located in the hut in front of you).
2. Assassin's Mark - (Video) - Turn around and continue down the path, clicking on [npc=83615] to loot the [item=113577]. Most of the [npc=83615] have [npc=83653] guarding them, in partial stealth-mode.
• Once you have looted the [item=113577] travel south, on the downhill path, to coords 53.5, 27.5 and turn in this quest.
3. The Power of Poison - (Video) - Activate the [item=113587], for this quest, and proceed to the Harvest Pits in front of you.
• Extrinsic Motivation - Kill 4 [npc=83749], 3 [npc=83706] and 1 [npc=83760].
• If you have killed your designated mobs, but haven't completed The Power of Poison, continue with attacking Shattered Hand mobs until you have completed that step.
• Turn in the quests at coords 53.5, 27.5 to [npc=83773].
4. Gardul Venomshiv - (Video) - Travel southeast to Shattered Rise, at coords 56.2, 34.0, and fight [npc=83834]. You will get him to about 10% health, and he will blind you and run up the path.
• Proceed to coords 57.1, 34.5 and turn in the quest to [npc=83904].
• NOTE: While following the path on Step 4, you can loot [object=234461] treasure (at coords 54.3, 32.5) behind some barrels, which will grant you 100 [currency=824].
5. We Have Him Now - (Video) - Travel up the path, and turn left looting 6 [item=113630] until you reach coords 58.2, 33.5.
• Finish off [npc=83923] and loot [item=113635] from his corpse.
• Turn in the quest to [npc=83904] at coords 57.1, 34.5.
6. No Time to Waste - (Video) - Use your [spell=168487] and click on [npc=84261] at coords 39.7, 60.9, and select "Administer the antidote to Kolrigg."