Holmes, retired to Sussex, is drawn into a last case when his arch enemy Moriarty arranges with an American gang to kill one John Douglas, a country gentleman with a mysterious past. Holmes' methods baffle Watson and Lestrade, but his results astonish them. In a long flashback, the victim's wife tells the story of the sinister Vermissa Valley.
After Sheriff Ken puts money in the safe, his brother Clem gives Rawhide the combination. With the money gone the disgruntled townsmen make Boots Sheriff and lock up Ken. Clem, now a prisoner of Rawhide, has a change of heart and sends Ken a message with the outlaw's location. Ken escapes by impersonating the saloon entertainer and rides for the hangout.
Philo Vance, accompanied by his prize-losing Scottish terrier, investigates the locked-room murder of a prominent and much-hated collector whose broken Chinese vase provides an important clue.
Infamous burglar "The Bat" commits a daring jewelry theft despite heavy police presence. Soon after, a bank theft occurs, which may be the work of the criminal as well. Meanwhile, Cornelia Van Gorder has various people arrive at her old mansion, including her niece, Dale, a bank employee, and police detective Anderson. When guests start turning up dead, Cornelia begins to suspect that The Bat may be lurking around the estate.
A kindly but desperate Alsatian innkeeper named Mathias murders and robs a rich Jewish merchant staying at his inn, but the ghost of his victim will not let him rest. Meanwhile, a mysterious Mesmerist has come to town, claiming he has made many criminals confess their crimes...
Three sideshow performers form a conspiracy known as "The Unholy Three" - a ventriloquist, midget, and strongman working together to commit a series of robberies.
Francis, a young man, recalls in his memory the horrible experiences he and his fiancée Jane recently went through. Francis and his friend Alan visit The Cabinet of Dr. Caligari, an exhibit where the mysterious doctor shows the somnambulist Cesare, and awakens him for some moments from his death-like sleep.