The Blue Diamond

We present to the attention of detective genre lovers the novel by Swedish writer Otto Witt "The Blue Diamond".
Lilly, the daughter of a Swedish aristocrat, is celebrating her twentieth birthday. Among other gifts, she received a blue diamond. The girl asks one of her admirers to replace the diamond with a fake stone, as she wants to sell the real one. The plan works, but then the diamond disappears...
The book features the complete unadapted text of the novel with comments and a dictionary.