Richard Harding Davis 
The Lost House [PDF ebook] 

Austin Ford, the London correspondent of the New York Republic, is spending some idle time in the American Embassy chatting with the Second Secretary, when suddenly a note is brought in. This note is an appeal for help, found in the gutter in a dark alley. The writer claims to be a young girl, who is kept against her will locked up in a lunatic asylum by her uncle. Although the Second Secretary tries to convince him that there is nothing to it, the journalist is determined to follow the lead.