The discovery of a gifted scientist falls into the wrong hands, bringing what at first appears to be a lifesaving miracle, but ultimately the untimely death of his closest friend.

When an astronaut returning from Mars discovers an alien aboard ship, he must face the loss of his shipmates, and make the ultimate sacrifice in order to prevent the alien from reaching Earth.

A chaste co-ed is enveloped by a strange power that gives her an insatiable sexual appetite, which is perpetuated by encounters with consenting men who, after making physical contact, morph into her body and disappear.

When Andrew McLaren is fired from his job at Anderson Technology, he suspects that he's being let go because the company president doesn't want to give him credit for his work on the CPS-1200, an as-yet untested time machine. Defiant, Andrew decides to take a trip in the machine. When he reaches his destination, two days in the future, his head is throbbing with a migraine and he is shocked to find that the police are looking for him. Fleeing the lab, he returns home to discover his wife lying in a pool of blood and a man fleeing the scene in a car. Shocked at his discovery, Andrew is determined to use his time machine to change what happened.

Anne Reynolds is a cold young woman, estranged from her mother, Laura, haunted by memories of her dead father and terrified of intimacy of any kind. Then one night, while repairing a flat tire she is attacked by a mugger. Severely wounded, she dies on the operating table only to come back to life five minutes later. However, it soon becomes clear that something inside her has changed. Anne learns she was one set of Siamese twins and her mother agreed to an operation that killed her sister, Marie, while allowing Anne to live. Now the remnants of Marie are starting to assert themselves changing Anne.

After her husband is killed in a car accident, Nancy Henninger rents out her backyard apartment to try to make ends meet. But her teenage son, Zak, is suspicious of her new tenant, Harry Longworth, who says he has come to the suburban community of Hunterville to set up a new factory for his company. When three people disappear from town Zak decides to conduct his own investigation.