The Last Dinosaur

Following the failed expedition, Maston Thrust Jr. resolves to mount a return mission to the ice valley to study the rumored dinosaur. He recruits geologist Chuck Wade, hunter Bunta, a Maasai tracker, Dr. Kawamoto, and Frankie Banks, a Pulitzer-winning photographer chosen by the press pool. Frankie convinces Maston to include her on the expedition by seducing him.

The Polar Borer carries the team to the valley, where they spot Pteranodons overhead. They raft to the shore and narrowly avoid being trampled by a towering Uintatherium. The opening days set a perilous tone for their mission.

After setting up camp, Maston, Chuck, Bunta, and Frankie head into the valley to locate the T. rex. Kawamoto stays behind to guard the camp. Their search marks the start of direct confrontation with the predator.

The party encounters the T. rex and barely escapes its initial attack. The creature later locates the camp, destroys it, and kills Kawamoto. It steals the Polar Borer and uses it to carve a canyon, releasing a Triceratops that clashes with the rex, and the rex finishes the clash by killing the Triceratops.

Returning to the now-destroyed camp, the group discovers Kawamoto and the Polar Borer are missing. Enraged, Maston swears to kill the dinosaur and recover his equipment. The mission shifts from exploration to survival and vengeance.

Months pass as the survivors live in a cave and defend against rival cavemen with a handmade crossbow. They befriend a cavewoman named Hazel, who becomes part of their small community. Frankie adapts to life in the valley as the rex threat lingers.

The T. rex returns and attacks the cave where Frankie hides. Maston, Bunta, and Chuck fend it off with a large boulder tied to its tail, buying time to pursue their plan. Maston resolves to kill the tyrant with a catapult.

While the catapult project progresses, Chuck finds the Polar Borer buried nearby and learns it is still operable. The team plans to use the Borer to boost their chances in the final fight. Maston remains determined to see the rex dead and refuses to abandon the valley.

Chuck and Frankie depart to repair the Polar Borer and then leave the valley, while Maston and Bunta stay behind to defend the site.

The Borer is launched back into the water as a signal to abandon the expedition; Frankie returns to plead with Maston to leave with them. In the night, Bunta is killed by the T. rex while it stalks the group, raising the stakes.

Frankie reunites with Maston and helps him operate the catapult against the T. rex, but the beast rises again and destroys the device. The valley remains perilous as the plan to defeat the rex hangs in the balance.

Wade arrives and urges immediate departure to avoid being trapped in the valley. Frankie pleads for Maston to come with them, but he chooses to stay behind. Wade and Frankie depart aboard the Polar Borer, leaving Maston and Hazel alone in the valley.