Codename: Sugarplum is an add-on for Fallen London, a browser-based choose-your-own-adventure game set in "Fallen London", an alternative Victorian London with gothic overtones. Codename: Sugarplum was originally the Exceptional Story for June, 2022.

“Where would a dachshund go if a dachshund decided to disappear? The Fifth City has innumerable nooks and crannies. Every alley, every shadow, might conceal a clue – or a lost dog. Sometimes, as a sleuth, the only thing to do is put boots to cobbles.” A journalist from the Surface has lost her pet dachshund, and contracted you to retrieve him. How hard can it be to find a missing dog? Just follow the clues, infiltrate a few undercover networks, expose a vast conspiracy in the Great Game, uncover the dark secrets of the sugar substitute industry, and you’ll be back in time for tea.