(A third of the way through The Insidious Dr Fu-Manchu published in the UK under the alternative title The Mystery of Dr Fu-Manchu. Petrie and Smith have been called to the house of Sir Lionel Barton as, despite Smith's warnings, they have received a telegram that he has been murdered.)
They arrive at the library and are surprised to encounter "...a young puma, or a civet-cat, or something..." just hanging about the house. Clearly Sir Lionel was an unconventional gentleman.
Smith had arrange for Scotland Yard to post a constable outside, and he reported that nothing had happened until half past ten when a young lady (gasp), Miss Edmonds the shorthand typist*. It seems she had left her bag behind. Arriving she went into violent hysterics. The policeman rushed in. "He saw a negro footman—there isn't an Englishman in the house—trying to pacify the girl out in the hall yonder, and a Malay and another colored man beating their foreheads and howling. There was no sense to be got out of any of them, so he started to investigate for himself." The library was locked from the inside. Through the window he saw the Egyptian Mummy case lying on it's side and Sir Lionel lying face down on top of it. Breaking in, he then sees a sort of green mist, or as the book puts it "A sort of GREEN MIST."
Just outside the door was a dead Chinaman. "A dead chinaman!" exclaims Smith. "A dead CHINAMAN," repeats the inspector. Sounds like a clew!
However entering the library they discover something unexpected; the body is not Sir Lionel, but instead his secretary, Strozza. Inspecting the other body it turns out to be Kwee, Sir Lionel's servant. Well, this has got confusing rapidly. Strozza was wearing Sir Lionel's dressing gown** and no one who knew him had looked closely at the body! Smith deduces that only Strozza knew Sir Lionel was absent as the other servants seemed convinced he was dead. It seems that Strozza, taking advantage of his absence, had decided to wear Sir Lionel's clothes and rifle through his sarcophagus; meanwhile Kwee for his own inscrutable reasons was hiding in the conservatory, waiting for his own opportunity to enter the library. Something (the green mist) had come out the mummy case and killed them.
Smith also concludes that Fu-Manchu is behind the scheme. "The presence of a concealed Chinaman surely is sufficient. Kwee, I feel assured, was one of the murder group, though probably he had only recently entered that mysterious service."***
Sir Lionel returns; he had been to see Professor Rembold at The Traveler's. He concludes that Strozza was after the jewels in the case. Professor Rembold had warned Sir Lionel not to open the sarcophagus. It seems that this was from the tomb of the priest Mekara, one of the magi who contended with Moses. The last time one of these was found, by M Page le Roi, the discoverer was found strangled. It seems that as well as Fu-Manchu, there's also Ancient Egyptian magic at large in the world.
Having (possibly) escaped on assassination attempt by Fu-Manchu thanks to a cursed mummy, Smith suggests to Sir Lionel to accompany him to a hotel as that's bound to make it impossible for Fu-Manchu to find him, I mean seriously Smith, what has happened to your paranoia here? Oh well.
* We may recall from the previous chapter that Sir Lionel was dictating at two hundred words per minute; clearly she is a skilled professional.
*** Just because you're paranoid doesn't mean they're not out to get you, yet Smith has admitted to wondering if Fu-Manchu might be behind every suicide, accident or murder he reads about; a Chinese person being in an unusual place seems sufficient for him to add them to the conspiracy. I think he's in danger of reading too much into things.