Holmes and Watson board a passenger train bound from London to Edinburgh, to guard the Star of Rhodesia, an enormous diamond worth a fortune belonging to an elderly woman of wealth; but within the first hour of the trip, the woman's son is murdered and the diamond stolen and any of the passengers in their car could be the killer thief.

On a Greek island during the 1912 war, several people are trapped by quarantine for the plague. If that isn't enough worry, one of the people—a superstitious old peasant—suspects a young woman of being a vampiric demon.

A scientist working on cures for rare afflictions, such as a bone softening agent made from molds to allow him to correct the spinal deformity of his nurse, finds the physical causes of lycanthropy in wolf-man Larry Talbot and of vampirism in Count Dracula, but himself becomes afflicted with homicidal madness while exchanging blood with Dracula.

London, 1761. St. Mary's of Bethlehem, a sinister madhouse, is visited by wealthy people who enjoy watching the patients confined there as if they were caged animals. Nell Bowen, one of the visitors, is horrified by the deplorable living conditions of the unfortunate inhabitants of this godforsaken place, better known as Bedlam.

Italy 1757, Pippo Popolino, a lowly tailor, disguises himself as the great Casanova in order to romance the attractive widow Francesca. He little suspects what awaits him... Locked into the incongruous role by the desperation of the real Casanova's creditors, Pippo must journey to Venice on a delicate mission far beyond his capabilities.

A fugitive, dangerous madman reaches an English village where he confronts his former partner who left him for dead in the jungle after their discovery of a diamond mine. When the former partner also claims to have since lost the mine and all its wealth, which he took all for himself, and though the partner is still living in a state of luxury , the madman takes up an offer from a crazed scientist to make him invisible, something the scientist has already done with experimental animals, so that he can take revenge.

Set in the eighteenth century, Moonfleet is about John Mohune, a young orphan who is sent to the Dorset village of Moonfleet to stay with an old friend of his mother's, Jeremy Fox. Fox is a morally ambiguous character, an elegant gentleman involved with smugglers and pirates.

Honest Robert Maynard finds himself serving as ship's surgeon under the infamous pirate Blackbeard.

A smooth-talking French thief wangles his way into an important position as prefect of police.

In Victorian era London, the inhabitants of a family home with rented rooms upstairs fear the new lodger is Jack the Ripper.