On December 4th…

December 4, 1878: Mary Morstan visited the Langham Hotel. [SIGN]
December 4, 1888: Francis Hay Moulton moved to 226 Gordon Square. [NOBL]
December 4, 1888: Lord Robert St Simon married Hattie Doran. [NOBL]
December 4, 1888: Hattie Doran disappeared. [NOBL]