The Fool is based on the thoughts and words of these street traders, beggars, artisans, thieves and performers of London on one hand, and on the letters and diaries of members of the upper classes on the other.

The narrative is grounded in the double life of a humble clerk who poses as the reclusive, but widely respected "Sir John."

He thus moves in wealthy upper class circles and participates in grand investment schemes while living in a London slum, showing the contrast between the world of the very poor and that of the very rich.

Dennis Clunes described Edzard's colourful film as "an unsentimental satire of scandalous cross-classing" with alternating scenes of the high and low life of 1857 London, "evoking a "richly detailed Dickensian milieu.

"[8] Variety admired Edzard's “research and topnotch design with street characters based on interviews by 19th- century social journalist Henry Mayhew”, which were “fine on their own terms, right down to the dirt under their fingernails."