As is usual with Wallace's works, The Secret House gallops off to a cracking good start with a fellow being interviewed for a job as assistant to the editor of a scandal rag called The Gossip's Corner -- an editor whose face is concealed during the interview by a bag-like fine silk veil tied under his chin. That would give most people pause, but the applicant takes it in his stride and gets the job.
Not long afterwards a millionaire named Farrington overhears two men arguing virtually on his doorstep about turning in the notorious blackmailer Montague Fallock, a man of whom there is no known photograph. Suddenly two shots ring out and both men lie dead.
Naturally when the police arrive Farrington's house is searched. Assistant commissioner T. B. Smith of Scotland Yard (who happens to live in the same London square) discovers the millionaire's area door is ajar. Not only that but he also picks up a gold scent bottle with the same perfume he detected in Farrington's hall although it is not that used by Doris Gray, Farrington's niece and ward. The only other clue is a silver locket engraved with a couple of lines whose meaning is unfathomable, discovered on one of the dead men.
Among other characters, the reader meets Frank Doughton, who loves Doris, adventurer Count Paltavo, Doughton's rival for her affections, Lady Constance Dex, friend to Farrington and Doris, and Dr Fall, physician to Mr Jim Moole. Mr Moole is the never seen eccentric owner of The Secret House in the village of Great Bradley, and many are the stories told about him.
My verdict: The plot is a rich stew of sinister foreigners, fraud, murder, the search for a missing heir, a most peculiar will left by a suicide, disappearances, rooms that change in the twinkling of the proverbial eye, revenge, and much more besides. While some elements are far- fetched, still it's one of those yarns carrying the reader along at a breakneck pace until an unusual denouement putting Smith in danger of...well, better not say, but as a hint alert the reader to consider the estate on which stands The Secret House.