Originally Posted by glObalist
"Gaining the Poisons Skill
At level 20, rogues are able to begin a quest chain which ends with the acquisition of the Poisons skill. The exact quests depend on the rogue's faction.
For Alliance, go to the Old Town in Stormwind. Master Mathias Shaw at SI:7 headquarters offers the first quest in the chain, Mathias and the Defias. The quest takes place in a tower on the southern border of Westfall near Stranglethorn Vale, along the river, and requires a skill level of 70 in Lockpicking to complete. After completing Klaven's Tower, the second quest in the chain, you will gain the Poisons skill and also learn the recipe for Instant Poison.
For Horde, go to the Cleft of Shadow in Orgrimmar and perform The Shattered Salute. The Horde quest chain is difficult to complete solo at level 20, but two level 20 characters or a solo rogue around level 23 should be able to complete it. The two main quests in the chain take place in a tower in the northeast corner of the Barrens. When the quest objectives are completed, the rogue will be poisoned with a very slow-acting poison debuff. After turning in the quest at the Cleft of Shadow, the rogue travels to Tarren Mill in the Hillsbrad Foothills, where they will be cured of the poison debuff (though the poison is easily curable through a variety of other means as well) and gain the Poisons skil"
Thanks, I know the quest
The issue was that I abandoned it, and now I am unable to get it back from the questgiver.
I contacted a GM today, so Ill see what they come back with.