You carefully close the spigot in the control panel, watching the cauldron's putrid ichors drip into the empty bottle.
With the poison in hand, it is time to return to High Priestess MacDonnell at Chillwind Camp to complete the mission.
Congratulations <name>, you've unlocked the last cauldron for us! Alchemist Arbington will soon know what this cauldron requires as far as reagents needed for the mix.
As for you, I am sure that Commander Valorfist will want to thank you personally for the assistance you've given us. Without you, our struggle against the Scourge would have been nearly insurmountable. Thank you, hero!