Veteran Secret Service agent Frank Horrigan is a man haunted by his failure to save President Kennedy while serving protection detail in Dallas. Thirty years later, a man calling himself "Booth" threatens the life of the current President, forcing Horrigan to come back to protection detail to confront the ghosts from his past.
Calvin Drake employs a group of low-lifes to drive away land owners along the path of a new railroad; Red Ryder opposes this strategy.
A secretary is found dead in a White House bathroom during an international crisis, and Detective Harlan Regis is in charge of the investigation. Despite resistance from the Secret Service, Regis partners with agent Nina Chance. As political tensions rise, they learn that the crime could be part of an elaborate cover-up. Framed as traitors, the pair, plus Regis' partner, break into the White House in order to expose the true culprit.
During an historic counter-terrorism summit in Spain, the President of the United States is struck down by an assassin's bullet. Eight strangers have a perfect view of the kill, but what did they really see? As the minutes leading up to the fatal shot are replayed through the eyes of each eyewitness, the reality of the assassination takes shape.
A police detective is caught up in a plot to steal two million dollars in bonds.
Dr. Mabuse and his organization of criminals are in the process of completing their latest scheme, a theft of information that will allow Mabuse to make huge profits on the stock exchange. Afterwards, Mabuse disguises himself and attends the Folies Bergères show, where Cara Carozza, the main attraction of the show, passes him information on Mabuse's next intended victim, the young millionaire Edgar Hull. Mabuse then uses psychic manipulation to lure Hull into a card game where he loses heavily. When Police Commissioner von Wenk begins an investigation of this mysterious crime spree, he has little to go on, and he needs to find someone who can help him.
Prior to the United States' involvement in World War II, the masked vigilante Spy Smasher fights Nazi agents operating within the US, led by the treacherous sabotage leader codenamed The Mask.
A young girl journeys to Africa to find her father, an explorer who vanished in the jungle.
Beyond Hell's Gate Pass is territory controlled by a man who calls himself King Carter; he uses a variety of schemes to prevent the railroad from being built, for fear it will finish his control of (what he considers) his land.
Mota is a Martian representative, who has come to impose interplanetary law on the Earth (which has become too dangerous); opposing his authority is Kent Fowler, who resists the alien plot, without understanding its details.
The obsessive scientist Dr. Miller is working on a matter-transmitter invention called the Paratron; a conspiratorial team of spies and no-goods pursue him to Alaska, trying to steal the device.
Dusty Bates observes some smuggled jewels hidden in a crate aboard a ship; he is pursued by low-lifes when the crate is put ashore.
Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.
Reporter Brenda Starr and her photographer Chuck Allen get involved in a search for the loot from a payroll robbery. Cliffhanging action and adventure and a fair amount of comic relief follow them at every turn.
Dr. Ernst Grood , having already dominated the planet Ergro, now intends to take over the control of the Earth. Unfortunately for him, reporters oppose his sinister designs.
Greedy traders have kidnapped a researcher, hoping he will reveal the location of a treasure in a hidden village. Family and friends of the researcher come looking for him. Adventure ensues.
A team of two-fisted insurance investigators (one of whom disguises himself as The Masked Marvel) endeavor to discover and thwart the loathsome saboteur Sakima.
Congo Bill is hired to locate an heiress lost somewhere in Africa.
A Martian invader crashes his spaceship conveniently close to the workshop of a scientist who is developing an interplanetary craft. If the extraterrestrial Purple Monster can complete the rocket ship and return to Mars, he will be able to start a full-scale invasion of Earth. Good thing Craig Foster sets out to thwart the Monster's mission!
Claire Forrest seeks her kidnapped scientist father, hidden somewhere on Mystery Island. He is held and forced to work on diabolical inventions by Captain Mephisto, a costumed villain.