Pen­ny feels cer­tain that some­thing is fol­low­ing her down the hall as she walks with her class through the Nat­ur­al His­to­ry Muse­um. She looks — noth­ing. She looks again — still noth­ing. She looks one more time and spies a ver­rrrry long neck and a ver­rrrry long tail on some­thing that looks sus­pi­cious­ly like a baby brontosaurus!

Pen­ny might be only five, but she knows dinosaurs are extinct. And yet, one seems to be fol­low­ing her. The lit­tle dino and Pen­ny spend time togeth­er all over the muse­um, and when Pen­ny doesn’t see a giant adult dinosaur lum­ber­ing around, she real­izes Pip — as she’s named him — must be on his own. The only thing to do is to feed him some snacks and take him home with her … if she can fig­ure out how.