Best movies like The Great Radium Mystery

Martians come to Earth to build an H-bomb strong enough to blast Earth out of orbit so that Mars can be moved into its place in closer proximity to the sun. Super-scientist Larry Martin, inventor of the first stratospheric-flight spaceship as well as a jet-powered personal flying suit with helmet, is called upon by the government to investigate ramped-up UFO reports occasioned by the Martians' spaceships. The Martians, meanwhile, led by Marex, engage a renegade earth scientist and a gaggle of gangsters to help them steal supplies, operate a menacing robot, and build their bomb. This movie serial in 12 chapters was originally planned as a sequel to "Radar Men From The Moon" with Commando Cody as the hero but at the last moment the main characters' names were changed and all other references to that serial removed from the script.

Pretty Girl Barbara Mededith takes over her murdered brother's crusading newspaper. She also assumes the dead sibling's identity as "The Black Whip," righting the wrongs of Crescent City very much in the manner of her famous ancestor, Zorro.

In a post-nuclear future, crime has been eliminated in the city of Soleil through a strict class structure imposed upon the population. Two illegal young lovers are enticed into becoming criminals by a shady guy who promises them a way out of the city so they can continue their lives in peace.

Superhero Captain America battles the evil forces of the archvillain called The Scarab, who poisons his enemies and steals a secret device capable of destroying buildings by sound vibrations.

Eric is a secret agent currently working as security guard for senator Dilly. The senator is the main advocate for a new kind of police officer: the Tracker, a perfect and nearly invulnerable android. When Eric realizes that senator Dilly is playing dirty games, he does not only have Dilly's security chief Ross after him, but also those nearly undefeatable Trackers.

A marine biologist and a government agent investigate mysterious deaths and rumors of a sea monster in a secluded ocean cove, and find themselves involved with a marine biology professor conducting secretive experiments, international spies trying to steal his secrets, a radioactive light on the sea bottom, and the malevolent thing which guards it.

During the Spanish Civil War, an agent on a mission to purchase coal meets with murder and counterspies.

A young heiress of an American gun factory is threatened by a masked man after her father was murdered. This criminal might be a member of her family or a German agent, who wants to get information about the factory's products, perhaps his mystery has a combined solution - we will probably never know...

James Houghland, inventor of a new method by which television signals can be instantaneously sent anywhere in the world, refuses to sell the process to television companies, who then send agents to acquire the invention any way they can. On the night of his initial broadcast Houghland is mysteriously murdered in the middle of his demonstration and it falls to Police Chief Nelson to determine who the murderer is from the many suspects present.

A mad scientist uses an army of androids and a device that can disintegrate metal to try to steal microchips containing top secret information. The government dispatches a beautiful female agent to stop him.

When the ancient continent of Mu sank beneath the ocean, some of its inhabitant survived in caverns beneath the sea. Cowboy singer Gene Autry stumbles upon the civilization, now buried beneath his own Radio Ranch. The Muranians have developed technology and weaponry such as television and ray guns. Their rich supply of radium draws unscrupulous speculators from the surface. The peaceful civilization of the Muranians is corrupted by the greed from above, and it becomes Autry's task to prevent all-out war, ideally without disrupting his regular radio show.

A famous scientist invents a humanoid robot (the titular "monster"), so a greedy rival scientist plans to steal it for use in his criminal plans. His henchmen often kidnap a trained gorilla (the titular "ape") from the zoo, to aid in the schemes.

Escaped Prisoner 39013 impersonates the rich and influential Horace Granville, allowing him to create a variety of disasters. Fortunately, he is thwarted repeatedly by three daring circus daredevils.

Jungle Jim fights enemy agents who are trying to steal cobalt while disguised as crocodiles.

A federal agent sets out to track down his partner's killers.

By a daring ruse and inside help, Pete Rennick, a noted criminal behind bars on federal charges, escapes from the prison, and all of the law-agencies and local police are out to catch him with roadblocks and every car searched, but the escapee gets away. Bill Hasford, a private detective, investigating a racket finds it leads to the wanted man, and has the biggest adventure of his career.

Alice Grayson's uncle develops a wireless torpedo that can be controlled by radio. After he announces his invention to several of his colleagues, two of them murder the scientist, steal the blueprints and prototype, and make plans to sell both to the highest bidder. When Alice discovers the identity of the thieves, the intrepid heroine, with the help of Bob Moore, her two-fisted boyfriend, desperately tries to recover the plans and torpedo before enemy countries can unleash the torpedoes against American ships. (IMDb)

Feature version of the 1951 American serial film, "Zombies of the Stratosphere".

After dense matter from an imploded white hole hits Earth, the planet's rotation is devastated. A group of government agents must locate a lost satellite network that is the world's only hope for survival.

Government agent Daniel Leight has his radiation treatments sabotaged. He soon finds that he can now move at super speeds but only by risking metabolic damage which could prove to be fatal. 'Lightspeed' must now use his powers to go after old friend turned terrorist who is now a mutant half-snake called Python.

Working undercover on a human trafficking bust, maverick FBI agent Wade Dalton (Kaiwi Lyman), captures Serick Ibrayev (Sanjar Madi), a mysterious operative from the Mongolian underworld. With time running out, Wade must escort Serik back to Mongolia, and team up with hard-boiled police detective Ganzorig (Amra Baljinnyam), to deliver Serik to court to testify against a crime Syndicate that will do anything to stop them.

Two federal agents battle a gang that hijacks trucks carrying materials vital for the security of the country and sells them to foreign powers.

A female team of government agents, under the guise of owners of a popular worldwide franchise of aerobic centers, matches wits with a group of criminals who have kidnapped a top defense specialist and his ailing son, intending to sell him to the highest bidder.

A wealthy young athlete comes to the aid of a beautiful heiress, whose fortune is being threatened by two arch villains, The Great Master and Doctor Zulph.

Spies from Japan conspire to steal the Channing "preparedness" fortune and invade the United States, beginning in New York, then allying themselves with Mexicans across the border. They are stopped by the efforts of munitions factory heiress Patria Channing and U.S. Secret Service agent Donald Parr.

Rosalind Joy is a constantly imperiled heiress to a fortune in gold.

A group steals a death ray in order to terrorise the world into peace. The inventor and his daughter try to retrieve the death ray with the aid of a government agent.

An evil scientist known as "Mr. M." uses a drug he has developed called "hypnotreme" to help steal submarine equipment. Federal agent Grant Farrell is dispatched to find the mysterious villain and stop his nefarious plans.

Criminals steal a death ray that concentrates the rays of the sun. The inventor's daughter and a government agent try to retrieve it.

A police detective is caught up in a plot to steal two million dollars in bonds.

A prospector is murdered by The Cactus Kid and his gang, who hope to find the murdered man's goldmine. The miner's dog, Rin-Tin-Tin, recognizes the killers, who thereafter seek to use the dog to locate the lost mine. With the help of a government agent and a young girl, Rinty saves the mine and brings the bad guys to justice.

Roberts and Moore played an army scout and a pony express rider who come to the aid of settlers terrorized by a greedy rancher-turned-outlaw.

Hawk of the Hills (1927), a ten episode serial, re-edited into a five-reel feature length version released in 1929. Newhall, California. A band of Indians led by the half-breed 'The Hawk' terrorizes prospectors in a valley. When the old prospector Clyde Selby hits the mother lode, The Hawk plans to kidnap his pretty blond daughter Mary Selby. This kidnapping actually proves one of the lesser of the perils faced by the poor Mary. Laramie, a government agent, wants with the help of his friendly Shoshone Indian friends to extricate the damsel-in-distress.

A weathered CIA agent is thrown into a web of deception when he uncovers a rogue government plot to unleash a deadly drug on humanity.

Filmed in the Sierra Nevada mountains near Sonora, California, this Universal serial is Universal's 40th sound-era serial. Eagle Scout Bruce Scott, leader of Martinsville Troop Number One, and his pack sets off in search of lost treasure and finds adventure