Pinky is a boy whose favorite color is pink and who proudly owns twenty-seven stuffed animals. His best friend, Rex, is a sports-loving girl who owns exactly twenty-seven toy dinosaurs. They love having everything the same, and they believe that is exactly how best friends should be. But their perfect balance is thrown off during a fun trip to the museum with Pinky's dad and his pesky little sister, Amanda. When they visit the museum gift shop, they discover there is only one pink dinosaur left on the shelf. Naturally, both Pinky and Rex want it for their collections. The two best friends must figure out how to solve this tricky problem without ruining their day. In a surprising twist, little sister Amanda might just hold the key to sharing.