Miss Brown of X.Y.O.Miss Brown of X. Y. O. is a 1927 mystery thriller novel by the British writer E. Phillips Oppenheim. It was notable amongst thrillers of the time for its use of an everyday female character as heroine.SynopsisMiss Brown, a respectable London-based typist, is walking through the fog-covered streets of Kensington when she is urgently called in to type down a letter for Colonel Dessiter who has just killed a foreign spy and has been shot himself in the process. The message reveals an anarchistic plot to plunge Europe into a fresh war.