Dinosaurs Before Dark has Jack riding a freaking Pteranodon to return to the treehouse.
Danger in the Darkest Hour is Jack's greatest moment. He has to drive a bakery truck- with two Jewish children inside- past a Nazi checkpoint, and Kathleen has made the truck invisible with her magic so he can pass. But here's the thing: she never cast a spell at all, as she'd been temporarily cut off from her magic due to the hopeless situation she'd been stuck in. Jack pretty much drove past and fooled Nazi soldiers with nothing more than a boost of self-confidence. Talk about Balls of Steel.
In the movie there are a few Big Damn Heroes moments. The first one is where the dolphin Annie freed saving Jack from drowning. Next, Jack saves Annie from the pirates. Finally, Annie takes the bullet that was meant for Jack.
You gotta admit, two little kids going on adventures really starts to show their hidden badassery. Kind of, at least.
Think about the whole concept this book has created. A magic treehouse that can go to anywhere at any time, like a magic Tardis. That is completely cool.