This is an exceptional story, a part of Fallen London that requires additional money and is more self-contained than the rest of the story.
The focus here is mostly on the writing and on piecing things together. Someone is on the lookout for a very old and special soul. The further you investigate, the more you realize that you are reading a retelling of an ancient greek myth.
This story has a lot of lore about devils and the means they take to shape souls ot have the 'flavour' they like. It also introduces some iron coins that force devils to tell a truth to whoever holds it.
Some other players found this story to be a bit short or to have a disappointing ending. I don't remember being unsatisfied.