Charlie Chan is an agent of the US government working in Washington DC and he is assigned to investigate the murder of the inventor of a highly advanced torpedo. Aiding Chan is his overeager but dull-witted son Tommy and his daughter Iris.
One dark and stormy night, an escaped convict, an embezzler, a runaway daughter, her intended and her father, and a gangster take refuge in a remote inn called "The Black Raven" after the nickname of a second gangster who owns it; and murder ensues.
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.
A honeymoon couple in New York for one night of wedded bliss before he's to join the army, become involved with gangsters after they find a cadaver under their bed.
Rejected by the Army, Marines, and Navy for being too young, the punks help the war effort by throwing fruit at a shop they believe is owned by a Japanese American. Confronted by him wielding a short sword, the gang decides to come back at night but find him dead.
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.
Henry Courtney, a wealthy importer is found murdered and the famous DeNormand necklace has been stolen. The false testimony of two witnesses, Rand and Hobbs, puts Jim O'Brien in the shadow of the hangman's noose. Martha Courtney, widow of the murdered man and Jim's former sweetheart is convinced he isn't guilty, and promises crooked lawyer Roger Lanning the necklace - which Jim doesn't have - if he can arrange for Jim's escape. Rand and Lanning killed Courtney, but Lanning doesn't know that Rand has the necklace.
Two friends take jobs as truck drivers, unaware that the trucking company is being targeted by a gang of saboteurs who will stop at nothing, including murder, to stop them.
Topper is once again tormented by a fun-loving spirit. This time, it's Gail Richards, accidentally murdered while vacationing at the home of her wealthy friend, Ann Carrington, the intended victim. With Topper's help, Gail sets out to find her killer with the expected zany results.
In the middle of a pictorial lecture on his recent expedition to the Mongolian Desert, Dr. John Benton,the famous explorer, drinks from the water bottle on his lecture table, collapses and dies. His last words "Eternal Fire" are the only clue Chinese detective Jimmy Wong and Captain Street of the police department have to work on.
Dr. Bernard Adrian is a kindly scientist who seeks to cure a young woman's polio. He needs human spinal fluid to complete the formula for his experimental serum. Meanwhile, a vicious circus ape has broken out of its cage, and is terrorizing the townspeople. Can there be a connection?
When a police officer is murdered, Captain Street looks to Mr. Wong to catch the killer. Prime Suspect: Frank Belden Jr., whose father is a businessman well known for both his success and dishonesty. Mr. Wong faces increasing danger and is nearly executed himself as the investigation develops in treachery and complexity. As Mr. Wong follows the trail of dead bodies, he uncovers a jewel smuggling ring on the San Francisco waterfront and a case much larger than the death of a police officer.
When the plane owned by the "Yukon and Columbia Mail Service" crashes, RCMP Sergeant Renfrew (James Newill) and Constable Kelly (Dave O'Brien) suspect murder. Their suspicions are confirmed when Renfrew finds the control stick has been jammed, forcing the plane to fly in one direction until the gas ran out. Mine owner Louise Howard (Louise Stanley) reports that her superintendent is missing. The Mounties find him murdered and that too has been made to look like an accident. A new mail service pilot, Bill Shipley (Warren Hull), arrives. He had gone to training school with Renfrew but had been cashiered for misconduct. The Mounties discover that Raymond (Karl Hackett), who had been working for Louise, really owns the flying line managed by Yuke Cardoe (William Pawley.) They find proof that all the gold from the mine isn't being turned over to Louise, and suspect that Raymond and Yuke are stealing the gold and shipping it to Seattle by plane.
When an escaped circus gorilla appears to have gone on a murderous rampage, a threatened attorney calls on the detective trio of Garrity, Harrigan and Mullivan to act as bodyguards. In short order, we discover that there is more to the attorney than meets the eye, and the ape may be innocent after all. When a pretty young heiress faces peril, it's up to our heroic trio to save the day.