In The Secret Explorers and the Archaeopteryx Egg, dinosaur expert Tamiko and geology expert Cheng travel back to the age of the dinosaurs in an effort to rescue a dinosaur egg from destruction. However, to save the egg, the Secret Explorers first have to use all their courage and skills to outsmart a fierce Allosaurus, rescue a baby Stegosaurus, and find a way to attract an Archaeopteryx. Tamiko and Cheng soon find that, to succeed, they need to come up with some unusual solutions...