BROAD AS IT WAS COMPARED to the town-houses hemming it in on left and right, the part of the Opera House fronting on the Hay Market could not contain a whole theatre. As anyone would discover who entered into one of its triad of massive arched doorways, this was only a lobby. The auditorium proper, and the set-shops and backstage spaces, were all under a mountainous roof that loomed in the interior of the block like a mountain-range over an Alpine town, and threatened to bury the adjoining houses under an avalanche of roof-tiles someday. Tonight the roof was hidden by darkness, occasionally blushing a lambent red as a bonfire flared on the street below, and betraying the presence of silent watchers posted on its roof. It over-shadowed a stretch of Hay Market running some two hundred feet from Bell Inn on the north (rumored to contain a secret subscribers’ entrance, used by the Kit-Catocracy) to the even narrower and darker alley of Unicorn Court on the south (which, for those brave enough to follow it all the way to its dead end, gave access to the backstage). Overall this was neither the grandest nor meanest fabrique in London and one could easily go past it without a second glance; but it happened to be the place where a lot of Jacobite Tories had lit bonfires tonight. The squadrons of un-uniformed Tory cavalry that had roved through the district to intercept messages between Marlborough House and the Kit-Cat Clubb, or Marlborough House and Leicester House, had converged hither, and turned their attention inward, toward the fires they had lit and the carriage they had brought to bay, which was rumored to contain the Electoral Princess of Hanover, here in London to spy and to cabal with Whigs incognito . Not a one of them noted the sentries on the high dark roof of the Opera, who, for the last several minutes, had been busy with signal-flags. Those faced not towards the imbroglio in the Hay Market but west toward certain parks and undeveloped parcels of land, not far away, which in recent days had turned into strangely well-ordered Vagabond-camps.