Go to Stormwind Harbor and question Snivel Rustrocket about the supplies. Return with any evidence he gives you.
<Marion listens with horror as you tell her why you're trying to track down Snivel.>
You mean, he might've used some kind of chemical on me? Ew! I can't believe I fell for that fraud!
If he's finished all of his errands, he's on his way down to the docks to catch a ship to the South Seas! Whatever you do, <name>, you can't let him get away with this.
Hurry down to Stormwind Harbor before you miss him!