Jamie is exploring Ammonite Bay when he meets Tess. Tess is a member of Dinosaur Club who lives in Ammonite Bay too. She shows Jamie around, including her favourite place - a secret cave with fossils all over the walls. But what's that strange tunnel at the back? Together they go through the tunnel and they discover some dinosaur footprints. Jamie and Tess walk along them...and the two new friends find themselves back in the time of the dinosaurs! It's amazing, but dangerous too - and they'll definitely need help from the Dinosaur Club...