This quest is not available in game.
Travel to Stratholme and search the ziggurats. Find and return new Scourge Data to Betina Bigglezink.
You will have to delve deeper into Stratholme, <name>.
Beyond the first gates you will find the ziggurats. We know that the Scourge draws great power from these structures. Search the Ziggurats and return with any information that you may discover.