From the start of the novel, Osbourne establishes that Jack operates with caution in comparison to Annie’s more daring attitude. They each approach their journey to the time of the dinosaurs differently, but together, they find a balance between caution and daring that allows them to return home thrilled about their time there and the magic tree house.

Without Annie, Jack would never have entered the tree house, as he recognizes that they don’t know its owner. This comment introduces that Jack is cautious in comparison to Annie, who immediately “start[s] up the ladder” after he makes this observation (5). However, the narrative quickly shows that Jack can be tempted beyond his caution when something he loves is involved. In this case, he is pulled up the ladder by the idea that tons of books await him at the top.

When they arrive in the Cretaceous Period, their adventure into the tree house is mirrored by Jack’s hesitance about leaving the tree house and Annie’s immediate decision to exit and “boldly” greet the Pteranodon. His desire to learn is what encourages him to step out into the dinosaurs’ world, but his caution also guides him as he uses his resources to navigate meeting dinosaurs.