The fiery star of the company of players called Lord Westfield's Men, Laurence Firethorn, is hot for a lady, wife of the Lord Mayor elect. A tryst at London's Nine Giants Inn is arranged. Meanwhile, the lugubrious landlord of the actors' home base is laid even lower by a plot to take over ownership of the inn. A young apprentice actor is subjected to a horrible assault and a waterman pulls a mangled corpse from the Thames. The drama comes to a climax at the annual Lord Mayor's show as his barge moves grandly down the river....