This is an Exceptional Story for Fallen London. Exceptional stories are chunks of additional content for subscribers which can also be purchased separately.
This story takes a lot of strange terms, some of them very dark. One warning for a kind of content that might trouble a lot of people (even people who usually don't need warnings): (Spoiler - click to show)possible animal abuse. More specifically: (Spoiler - click to show)you can voluntarily choose to murder a sentient elephant and watch it die and get harvested for ivory. This is only a small side part of the story and not the main thrust.
In this story, there is a mysterious band of thieves that seems to be making enormous amounts of money, but without any apparent victims. Your job is to figure out who their victims are.
This ends up being tied to some of the deeper lore of Fallen London, specifically (names of factions it ties into): (Spoiler - click to show)Parabola, the chessboard, and the Red Handed Queen. It has some significant choices that gave me pause, and features a lot of duality, which is a favorite topic of mine to play in IF.
Overall, I would give this 4 stars, except it features a couple of concepts I personally enjoy quite a bit.