Rick Marshall was once a big shot paleontologist, but after a terrible interview on the Today Show ruined his career, he's since been stuck as a dead-end employee at the La Brea Tar Pits. He meets Holly Cantrell, a young student who subscribes to his old theories about the existence of time warps. She shows him a fossil, and Rick is astonished to find that it's a fossilized cigarette lighter-- stranger still, it's his cigarette lighter. She takes him to the cave where she found it, and he brings a machine of his invention that helps detect time warp particles. The cave tour guide, Will, rafts them into the cave, where suddenly, when Rick turns his machine on, the ground shakes and they plummet down the river into the middle of a desert. The desert is filled with artifacts from the past and present, which causes Rick to celebrate that his time warp theory was correct. They befriend a local primate, Cha-Ka, and they find themselves pursued by a giant Tyrannosaurus Rex, who hears Rick refer to it as stupid and develops a taste for revenge against Rick's insults. They stumble upon a race of walking lizard men called Sleestaks and receive a telepathic distress call from one of them. They learn one of these lizard men, Enik, was trapped in another dimension by a wicked Sleestak named Zarn who has plans to take over the Earth. Rick and his crew find a way to rescue Enik from his prison... but when they learn that Enik is actually the one bent on global domination, they must find Rick's machine and make it back to their time period before Enik leads a Sleestak army into their world.
Best part of story, including ending:
It's too long, and tonally it's kind of a mess, but it's still an enjoyable shaggy dog sci-fi comedy, with good performances from Ferrell and McBride.
Best scene in story:
At one point, Ferrell and McBride eat fruits with hallucinogenic juices, and the absurd visions that they have are the funniest parts of the film.
Opinion about the main character:
Rick is a classic Will Ferrell character: not terribly likable, because his ego is so huge, but he says so many silly and absurd things that you end up liking him anyway.