Dennis Letter the 15th is the fifteenth-generation descendant of Silvio Letter, an economist who created the decaying currency "L" roughly 250 years prior. Silvio designed this system to combat rampant capitalism and societal decay by ensuring money spoiled like perishable goods. While the "L" currency brought temporary peace, it sparked severe backlash from the Central Bank, which saw it as a threat. The Bank arrested Silvio and abolished the "L", reinstating the previous chaotic economy.

In response, pro-"L" rebels, including Silvio's son, established Chimney Town as an isolated refuge beyond the Central Bank's reach. To safeguard their society, they engineered a permanent smokescreen obscuring the sky, cutting off all visual and physical connection to the outside world. This entrenched the town's isolation and perpetuated the myth of the smoke being an eternal, natural phenomenon, discouraging questions about the universe beyond. Dennis Letter the 15th embodies this lineage, the rebellion's legacy, and Chimney Town's founding principles. His existence is intrinsically tied to the town's hidden history and its deliberate severance from external realities.