The fight with the Horror isn't marked with a check box or the FIGHT keyword. This makes sense, because, if it were a real FIGHT, it would fill a slice of the Vessel clock, which it shouldn't do. Is it mandatory given arrival in that map point? Or is it optional like a typical point action? Or, should I have read the title of the point and known not to go there unless I intended to finish the job? (I'm taking this last interpretation for now.)