Stromgarde Keep is one of the Syndicate's largest strongholds. Many of the organization's most important dealings take place behind its walls. I have received word of a certain trade taking place between members of the Syndicate somewhere in Arathi Highlands, and I'm certain the details of this trade can be found somewhere in Stromgarde. To infiltrate the keep without arousing suspicion, you'll need a disguise. See if you can find one among the Syndicate outside the keep, at Northfold Manor.