Nobita insisted that Dinosaur still survive, but Giant and Suneomake fun of Nobita’s idea, Nobita use Doraemon’s gadget ” ○ × Fortune Telling” to find the truth about dinosaur still alive on earth, but the answer is X (no).
However, Suneo saw a dinosaurs and start questioning himself at the end. Meanwhile, the Nobita and Doraemon create a underground Secret Base using “Anywhere Hole” and discover a large underground cavity. In the Underground Secret Base, Suneo are being separated from his friends, and left behind in the underground.
Nobita, Doraemon, Shizuka, and Giant went back to the Secret Base and found an underground world of Dinosaur.