Three years after being kicked out of the science department for his theory of Time warps, and his attempt on Matt Lauer's life, Rick Marshall is reduced to working as a teacher at the George C.

Page Museum until he meets Holly Cantrell whose finding urges him to create a tachyon amplifier to enable time warp travel. They go to the Devils Cave attraction where the finding was found, hiring its tour guide Will Stanton. But once they've activated the tachyon amplifier, losing it in the process, the three end up in a parallel universe where all timelines converge. They soon meet some ape men, Pakuni, two of whom were going to kill the younger one, when Stanton unintentionally gives the other two the secret of fire as they run off. The gang then proceed to help the other one, named Cha-Ka, until he runs off with them in pursuit.