I made a mistake and abandoned the quest, Report to the Keep, given by Gulug, in Orsinium. How do I get the quest back please?
Edited to add, I can't find Gulug in the bathhouse.
That objective is part of the larger Orsinium introductory quest Invitation to Orsinium. To start this quest again, you'll need to go to Merchant's Gate and find the dead messenger.