Here's how to find and use the Catalyst to upgrade gear, as well as get Harmonized Silk to power it, in WoW: The War Within.

In World of Warcraft: The War Within, you can find a machine known as the Catalyst that allows you to create tier gear.

How to Complete the Visions of Azeroth Questline in WoW Now that you have the requirements out of the way, you can get started on the quest proper.