Holmes and Watson travel to Sussex to investigate the murder of Squire Douglas, who was shot to death in a sealed-up castle, with only two apparent suspects.
Dr. Watson accidentally comes home from his club with another man's coat, providing an important clue when the other man is murdered late that same night.
Sherlock Holmes seeks a rational explanation for the Winthrop family legend, which foretells the death of any family member who unexpectedly finds silver coins in his possession.
Sherlock Holmes investigates a strange story told to him by a shopkeeper, who claims to have been a member of the 'League of Red-Headed Men' until it unexpectedly dissolved.
Holmes meets an injured man carrying an unconscious woman. The man is an engineer who was hired by a man to fix the large hydraulic press at his estate but when he arrived, his curiosity about the press' use got him and woman in trouble.
A Mr. O'Casey asks Holmes to find a man that he split the purchase of a lottery ticket 3 ways with, including a woman. They had torn the ticket into 3 pieces and the deadline to claim the prize is midnight.
A French translator named Dubec tells Holmes he was kidnapped and forced at gunpoint to translate a Frenchman being tortured. The parties were trying to get the man to sign some papers but he was refusing. Worse, Dubec doesn't know where.
Betty is being tormented by apparent hallucinations, latest is a "singing violin." Her stepfather tells her fiance there can be no wedding because she is going to be declared insane. When the fiance goes to consult Holmes, he is murdered.
Millicent Channing comes to Holmes asking help to find her fiance that disappeared. He had told her of his discovery that prompted him to visit Sir Greystone at his castle. The fiance didn't return and Sir Greystone denies ever seeing him.
Sherlock Holmes helps one of Dr. Watson's old friends by explaining the source of an odd noise in the man's home, but in doing so Holmes uncovers a more serious mystery.
A zealous suffragette acquires a bomb shaped like a croquet ball, intending only to draw attention to her cause, but it is switched with a real croquet ball and explodes, killing a member of Parliament.
Holmes is called to a boy's school in Belgium. A young student is in the monthly habit of writing the names of faculty members on the steps of a nearby church. Shortly afterward the person whose name was written down is found dead.
A young boy flees his compartment on a train and seems to have vanished into thin air. Although his governess thinks he has simply run away, Holmes suspects something a bit more serious and his investigation leads him to a nearby circus.
Alex, an advice columnist, advises a young woman, Susan, to break up with her violent fiancé. The groom-to-be pretends to be wealthy to mask his motive of acquiring the wealth of his intended bride. He beats Alex and threatens his life.
A baby is left on Holmes' and Watson's doorstep. The child turns out to be the daughter of a missing French scientist. Watson is attacked and the baby is kidnapped. Holmes must find the baby and father and avoid an international scandal.
Russell Partridge tells his wife Janet he murdered his six previous wives and that she has one day before he murders her, too. Janet can get no one to believe her except Holmes and Watson who must trap the killer before time runs out.
A traveling salesman is found hanged in his hotel room. Although the police eventually rule it to be a suicide, his widow thinks otherwise and asks Holmes to investigate the mysterious "suicide" further.
After a famous criminal is run over and killed by a milk wagon, Lestrade finds a coded note in the man's clothing. He asks Holmes to decipher it. The investigation leads him to assume the dead man's identity and follow the clues to Paris.
Sir Charles Farnsworth is found dead in his mysterious Farnsworth Castle. He had a clause inserted in his will that his death must be investigated by Sherlock Holmes. Holmes reveals traces of arsenic in the man's body and many suspects.
A condemned man scheduled to hang the next day uses his last request to ask Sherlock Holmes to prove his innocence of the murder for which he is about to be executed.
A political leader is being blackmailed, and to find the blackmailers, Holmes and Watson join a marriage bureau. However, things don't go quite as planned, and Holmes winds up getting arrested and thrown in jail.
As payment for solving a case, Holmes and Watson spend a weekend at an estate in the Balkans. However a fellow guest is poisoned and their host is accused of the murder. Holmes must find the real killer before he becomes the next victim.
A young boy asks for Holmes' help in finding his missing father. Holmes' investigation reveals the man is a gambler on the run from his creditors. The team makes the rounds of the seedy gambling underworld in search of the boy's father.
While walking along the banks of the River Thames, Watson finds a diamond tooth. The article takes on more meaning later, however, when Holmes learns that the body of a murder victim had been discovered near where Watson found the tooth.
A chemist is accused of the murder of his fiancé's stepfather, who was determined to keep the two apart. Although there is mounting evidence of the chemist's guilt, Holmes is requested by the old man's housekeeper to investigate the case, as she believes the young man to be innocent.
