Greg is warned against harvesting arok, a delicious fruit. But he can't resist and the smell of the fruit draws a massive Brontosaurus to the cave. The hungry beast traps the Butlers and their friends between arok and a hard place.
When the valley is attacked by voracious army ants, even the dinosaurs run for cover. The Butlers must save themselves and their new cave-dwelling friends by constructing a hot-air balloon to escape.
With the shell of an Archelon, the Butlers build a primitive submarine to help them explore a part of the valley ruled by a massive, hungry Tyrannosaurus Rex.
When a volcano threatens to erupt, the villagers believe it to be just the regular rumbling. John and Gorak must climb the beast, outwit a Terror Bird and find a way to divert the inevitable lava flow down to the village.
The Butlers inadvertently anger a tribe of primitive "missing links," and must prepare the village against an imminent attack. They're outnumbered, but they have ingenuity -- and fire -- on their side.
Kim Butler has fallen ill and only a group effort to collect ingredients for a medicine can help. Along the way, the clan runs afoul of a giant tortoise, a long-necked Elasmosaurus, a hungry Deinosuchus, and a determined mother Pteranodon.
Their pet Stegosaurus, Glump, is lost and Greg and Tana are worried. When they find him "treed" on an outcropping of rock by hungry wolves, they decide to dress in an old Smilodon fur to scare the wolves away.
When a quake unsettles a guardian statue's head, Gorak feels the clan must replace it. Bemused by his superstition, the Butlers build a wagon, encounter a Dimetrodon, and transport a boulder before realizing Gorak's feeling was right.
Lok is accused of releasing the villager's lucky hunting mascot, an adult Stegosaurus. Lok will be exiled if his friends and family can't unmask the real culprit, and release Lok from a high cliff, where he is held captive.
Tana sees a strange bird, and when she draws it in the sand, the Butlers recognize it as a plane that could finally rescue them. They build a radio transmitter and create an S.O.S. out of shells, one of which is stolen from a Plateosaurus.
A massive brush fire -- started by a people with nefarious, thieving intentions -- prompts the Butlers and their friends to build fire breaks and the valley's very first fire engine.
Several hungry Allosauruses invade the valley - and they aren't the only ones when the Butlers help an injured young man, the son of the Sky People chieftain, who assumes the worst. Only "hocus pocus, Diplodocus" and a catapult can help.
Primitive rodents pilfer the Butler's First Aid kit, which they track to a land ruled by ill-tempered weather and a worse-tempered Iguanodon. When both show up, it will take Greg's kite-flying prowess to help them cross a river and escape.
John Butler has built the valley's first glider plane, which he uses in a dogfight with a Pteranodon and to help search for Tana and Greg, who are downriver and threatened by thick fog, a Brontotherium, and a sharp-tusked Mastodon.
An eerie silence presages a stampede of animals of all sizes and epochs. In the swamp prowls a predator that is not of the valley - and Gorak, Lok, Katie and John Butler go to investigate. Meanwhile, Greg and Tana discover a toothy kitten.
When camel-riding night raiders from the other side of the mountain threaten the village, the Butlers devise a plan using a huge diamond-encrusted drill, natural gas and a pesky baby Styracosaurus to make the mountain pass unpassable.
