
Much of the speculation about the solution to the mystery centers around the cover illustrations, which had been drawn by Dickens’s son-in-law, Charles Collins. The monthly covers of Dickens’s novels were meant to foreshadow the plot without giving away the ending.
Charles Dickens. The Mystery of Edwin Drood. London: Chapman & Hall, 1870.

Sir Herbert Beerbohm Tree played John Jasper in a production of Drood at His Majesty’s Theatre in January of 1908. In this adaptation, a solution is offered: that Edwin Drood is alive and that John Jasper, in a haze of opium intoxication, only dreamt that he murdered him.
Rutter Collectiion, Print and Picture Collection

A film version of The Mystery of Edwin Drood, directed by Stuart Walker, was released by Universal Pictures in 1935. With the casting of veteran horror-film villain Claude Rains as Jasper, it was classified as a horror film. Forrester Harvey played Durdles.
Theatre Collection

Jasper encounters Deputy, a boy employed at the Traveller’s lodging house in Cloisterham, throwing stones at Durdles, a drunken stonemason and engraver of tombstones: “He gives me a 'apenny to pelt him home if I ketches him out too late.”
FOC Darley. Illustrations from the Household Edition of the Works of Charles Dickens.

The unidentified investigator who visits Cloisterham after Edwin Drood’s disappearance, Datchery announces himself at the Crozier Hotel, “where he put up with a portmanteau,” as “an idle dog who lived upon his means.”
Kyd. Illustrations of Characters in Dickens's The Mystery of Edwin Drood.

Hiram Grewgious is a lawyer and the guardian of Edwin Drood’s fiancée, Rosa Bud: he had been in love with her late mother. As Dickens describes him: “He had a scanty flat crop of hair, in colour and consistency like some very mangy yellow fur tippet (scarf).”
Kyd. Illustrations of Characters in Dickens's The Mystery of Edwin Drood.

Tope is chief verger (someone who assists in ordering religious service, especially in an Anglican church) at Cloisterham Cathedral and landlord of Jasper and later, Datchery. He is described as a showman, and “accustomed to be high with excursion parties.”
Kyd. Illustrations of Character s in Dickens's The Mystery of Edwin Drood.