The Millionaire Mystery

Fergus Hume was renowned as the bestselling mystery writer of Victorian times after his first book, The Mystery of a Hansom Cab, broke all records. In 1901 he returned to form with this ingenious tale, selected to represent Hume's prolific output by Collins' Detective Club panel in 1930. Cicero Gramp was, according to himself, a 'professor of elocution and eloquence' - to anyone else he was no more than an engaging and extremely craft vagabond.
Hence it was that he found himself awakened from his sleep in the corner of the churchyard, the cheapest available lodging, by men's voices at an hour past midnight. Two dark figures silhouetted for an instant against the white mausoleum where lay the body of the millionaire Richard Marlow. Then the turning of a key in the iron door of the vault. Silence. Two figures moving back into the night carrying a sinister burden - what Gramp guessed was the body of Marlow.
But when a search was made in the vault, Marlow's coffin was found shut, and not empty: only the body in it was not Marlow's but that of another man - murdered! And that is only the first puzzle in The Millionaire Mystery .