A scientist from the failed Philadelphia Experiment leads a team of Navy SEALs back in time to the Cretaceous Period to rescue the first team he sent back during the 1940s. Things go wildly awry though, when on his return he accidentally brings a giant, man-eating dinosaur back through the portal and into modern-day, downtown Los Angeles.

Office employee Barry Thomas is caught in a "time bounce" caused by a glitch in the company's secret project. Now the same day occurs again and again - and Barry's the only one who can do anything about it, including saving the life of beautiful research assistant Lisa Fredericks.

Hekule, the King of Kuvukiland, is given a gemstone by the dying Kunji Balanadin. The stone is cursed and causes Hekule to become possessed by the spirit of the mischievous Kunji. It is up Mr. Bones, the royal witch doctor to cure his King and get rid of this cursed stone by returning the gem to its home in an Indian fishing village.

On a class excursion to a cave with stone age paintings the clumsy Rex gets lost. A mysterious crystal opens a gateway in time and sets him back to the stone ages, where he meets a group of prehistoric fellows and the gorgeous Eba. While teaching her English and doing some pseudo-research on her fellows, his main goal is to get her sle...

In the not too distant future, corporations have taken over the world and sex is outlawed. A group of rebellious teens travel back in time to present day to try changing history to prevent that from happening.