A woman is married to the son of a doctor, the proprietor of a private sanatorium, where she is under unwilling treatment. Both the son and the doctor indicate they want the marriage dissolved. Arriving at the scene is a mysterious personage identified as the doctor's cousin who formerly was a stage magician in Europe. He is accompanied by a threatening dwarf.
Three childhood friends, Martha, Walter and Sam, share a terrible secret. Over time, the ambitious Martha and the pusillanimous Walter have married. She is a cold businesswoman; he is the district attorney: a perfect combination to dominate the corrupt city of Iverstown at will. But the unexpected return of Sam, after years of absence, deeply disturbs the life of the odd couple.
After three men are convicted of bank robberies, Charlie becomes suspicious. After some investigation Charlie finds the men are innocent and that the fingerprint evidence used to convict them had been forged. Charlie then proceeds to find the true bank robbers.
A convicted thief in Dartmoor prison hides the location of the stolen Bank of England printing plates inside three music boxes. When the innocent purchasers of the boxes start to be murdered, Holmes and Watson investigate.
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.
Sherlock Holmes investigates when young women around London turn up murdered, each with a finger severed. Scotland Yard suspects a madman, but Holmes believes the killings to be part of a diabolical plot.
Leo, a former convict, is living in seclusion on an island with his step-daughter, the daughter of his late wife. Leo was framed by a group of former business associates, and he also suspects that one of them killed his wife. He has invited the group to his island, tempting them by hinting about a hidden fortune, and he has installed a number of traps and secret passages in his home. He is aided in his efforts by a former cell-mate who holds a grudge against the same persons. When everyone arrives, the atmosphere of mutual suspicion and the thick fog that covers the island promise a tense and hazardous weekend for everyone.
Evelyn, an emotionally vulnerable and unstable woman, stays at the home of her doctor Dan Proctor. There she meets and falls in love with his brother, Douglas, who is happily married to Ann. Evelyn then sets forth to break up the happy marriage and win the love of Douglas.
During the Nazi occupation of Czechoslovakia, surgeon Dr. Franticek Svoboda, a Czech patriot, assassinates the brutal "Hangman of Europe", Reichsprotektor Reinhard Heydrich, and is wounded in the process. In his attempt to escape, he is helped by history professor Stephen Novotny and his daughter Mascha.
In the midst of World War II, Sherlock Holmes rescues the Swiss inventor of a new bomb-sight from the Gestapo and brings him to England, where he quickly falls into the clutches of the evil Professor Moriarty.
It is prior to the commencement of World War II, and Japan's fiendish Black Dragon Society is hatching an evil plot with the Nazis. They instruct a brilliant scientist, Dr. Melcher, to travel to Japan on a secret mission. There he operates on six Japanese conspirators, transforming them to resemble six American leaders. The actual leaders are murdered and replaced with their likeness.
The police arrest a man climbing over the wall of a cemetery after midnight. He claims that he is being blackmailed and is following instructions he received by mail to leave $1000 on a certain grave. It turns out that he's not the only one who got a blackmail letter from the same person--calling himself "The Black Panther"--and it also turns out that all the recipients are connected to an opera company.