At the suggestion of Huth I have created a number of hooks for investigative/horror games based on 1950s sci fi and horror movies.
1950
- Reports of flying saucers in a remote area of the country attract government officials, but the intelligence behind the saucers may not be "otherworldly" at all (The Flying Saucer)
- A government investigation into piracy leads to an island dominated by life from another epoch (Two Lost Worlds)
1951
- Scientists observing a mysterious body passing through our solar system believe an intelligence from it has landed in a remote location on Earth. This intelligence must be apprehended, and interrogated! (The Man from Planet X)
- Strange substances found in the South American jungle awaken alien parts of a white overseer's genome (Bride of the Gorilla)
- A group of arctic researchers and military personnel uncover a spaceship and the entity it contained (The Thing from Another World)
- A cosmic object is on a collision course with our solar system and threatens to wreck havoc. Experts must work to prevent the disaster or to otherwise ensure the survival of humanity. (When Worlds Collide)
1952
- Strange extraterrestrial transmissions seem to be coming from intelligent life. Is it a hoax or a genuine alien? Either way it could throw the world order into chaos. (Red Planet Mars)
- One of a number of lost airman is recovered, raving about a strange civilization unknown to man. (Untamed Women)
1953
- Investigators attempting to stop an alien plot find their inquiries blocked by the police. Could this be the result of mind control? (Invaders from Mars).
- Freed from its body, the brain of a sinister madman find it has new and terrible powers. (Donovan's Brain)
- Atomic testing awakens a creature not seen in millions of years. The creature begins a rampage through mankind's greatest cities. (The Beast from 20,000 Fathoms)
- Investigators learn mankind may be the true threat when they must decide what to do with the discovery of a benign group of extraterrestrials. (It Came from Outer Space)
- Astronauts threaten the Earth after being mind-controlled by extraterrestrial entities discovered while on a mission. (Cat Women of the Moon)
- Investigators awake to find that they are the last survivors of humanity and that the automated engine of man's destruction is seeking them out. (The Robot Monster)
- An unintelligent but seemingly monstrous phenomenon baffles scientists and threatens lives as it seeks to engulf a town (The Magnetic Monster)
1954
- An expedition into the remote wilds of the Amazon discovers a monster whose biology is completely inimical to human science. (Creature from the Black Lagoon)
- The bottom of the ocean may hold more terrible creatures than the farthest stars, especially when they decide to attack those on land. (Monster from the Ocean Floor)
- A mad scientist uses advanced (perhaps extraterrestrial) technology to create towering robot monsters. (Gog)
- Scientific experiments create horrendous monsters out of normal earthly creatures. (Them!)
- Aliens secretly encourage human exploration into science in the hopes that the resulting monsters will wipe out mankind. (Killers from Space)
1955
- An alien intelligence extends its hive mind to the animals and then humans of a small, isolated town. (The Beast with A Million Eyes)
- A criminal organization uses a scientist to create technology to aid in their crimes - including immortal zombies. (Creature with the Atom Brain)
- An astronaut returns to Earth infected with an alien organism that threatens the whole of humanity. (The Quatermass Xperiment)
- An attempt to put an inhuman monster on display ends disastrously when the creature is freed and terrorize the area. (Revenge of the Creature)
- A think-tank of scientists and politicians turns out to be a front for an alien conspiracy. (This Island Earth).
1956
- A mad doctor creates mutilated horrors out of human test subjects in order to better understand the nature of the body and the mind. (The Black Sleep)
- A mad dictator uses super-science to engineer his people into the perfect subjects. (The Gamma People)
- An alien invasion replaces people with identical replicas. (Invasion of the Body Snatchers)
- Explorers discover a subterranean civilization similar to a lost empire, but adapted to its fantastical surroundings. (The Mole People).
- Mysterious deaths in a mining community are the product of creatures awakened by nearby atomic testing. (Rodan)
1957
- An alien entity seeking to make contact with Earth comes from such an unearthly environment that its physical presence is poisonous to humans. (The Astounding She-Monster)
- Creatures created by atomic testing absorb the memories and intelligences of those they devour, allowing them to plan a world-wide empire. (Attack of the Crab Monsters).
- An alien renegade uses its powers to help it control humans in a remote town but is soon pursued by an alien of the same species that seeks justice. (The Brain from Planet Arous)
- A strange substance brought to Earth by a meteorite threatens to destroy a small town as it replicates incessantly. (The Monolith Monsters)
- A creature terrorizing an isolated village in a remote part of the world is actually a normal insect that was exposed do strange radiation when NASA shot it into space. (Monster from Green Hell)
- A group of seemingly-human like aliens attempt to take over the world with an advanced robot. (The Mysterians)
- An alien's mutilation of Earth creatures (including humans) is actually its attempt to find a cure for a terrible blood disease ravaging its home planet. (Not of this Earth)
- A man is turned into the living embodiment of a monster from folklore after conducting experiments on himself using animal blood. (The Vampire)
1958
- An organism deposited by a meteorite may hold the clues to early life on this planet, but the conditions now are such that the creature grows exponentially and becomes dangerous to humans. (The Blob)
- A sinister scientist uses advanced hypnotherapy to turn those seeking treatment into mindless slaves. (The Electronic Monster)
- A scientist's experiment turns him into a half-man half-monster and relegates his intelligence to a place incapable of dealing with his new form. (The Fly)
- An alien entity seeking to sabotage mankind's scientific advancement takes possession of human children. (The Space Children)
- A mysterious fog in a remote area is actually the portal to another world, and it unleashes a terrifying monster. (The Crawling Eye)
- Radiation gives a man strange powers that he turns towards crime and violence. (The H-Man)
- The strange behavior exhibited by a number of townsfolk may be evidence that they have been replaced by alien entities. (I Married a Monster from Outer Space)
- Experiments into ESP, telekinesis, and atomic radiation go awry, creating a thought-creature hungry for human brains. (Fiend Without a Face)
1959
- A scientists experiments on himself allow him to access other dimensions. At first he uses this for self-advancement (and even criminal pursuits) but soon realizes it has a horrible toll on his body and mind. (4D Man)
- A sink hole in Florida reveals that ancient monsters aren't just found in far flung locations. (Attack of the Giant Leeches)
- Invaders from another planet seek to conquer Earth using their power to make items invisible to the human eye. (The Invisible Invaders)
- A doctor seeking to end world hunger accidentally makes a group of giant, ravenous shrews. (The Killer Shrews)
- A scientist unlocks the secret to eternal life, but it requires him to take the brain tissue from living subjects. (The Man Who Could Cheat Death)
- Aliens take on the form of adolescent humans to hopefully catch human authorities with their pants down. (Teenagers from Outer Space)
- An attempt to arrest the aging process turns a woman into a hybrid insect creature. (The Wasp Woman)
Here's a bonus one from 1963, since Blue Oyster Cult wrongly thinks its from the '50s.
- A scientist's experiments with vision allow him to see things normally outside the human possibility space. What he sees causes misery and madness. (X: The Man with X-ray Eyes)